Investigations of the skyrmion Hall effect reveal surprising results
One step further towards the application of skyrmions in spintronic devices. Researchers at Johannes Gutenberg University Mainz (JGU), including MAINZ Director Prof. Mathias Kläui, and the Massachusetts Institute of Technology (MIT) have made another important breakthrough in the field of future magnetic storage devices. ...
Massive Open Online Course on Spintronic with MAINZ PI Mathias Kläui started
The MAINZ open-access page online learning tool in the field of spintronics is online. The online lecture series is focused on spintronics, one of the core research areas of the physics department, and is supported by the Graduate School of Excellence Mainz “Materials science in MAINZ”.
The format allows the students to self-pace the learning process, and repeat the lectures if needed. References are provided as a complementary material for each lecture. At the end of each lecture the student is presented with a set of closed-ended questions relative to the topic just described. This is meant to provide the student with an immediate assessment of the learning experience.
The first lecture is given by Prof. Dr. Mathias Kläui, University of Mainz, on ‘Domain Wall Physics’. Upcoming lectures will, for example, provide an introduction to magnetism, to the field of spintronics, and to quantum spins. All the lectures provide an introduction of the state of the art of the subfield aimed at physics/chemistry students and are taught in English so that they can be followed by students all over the world.
The course is accessed by http://bit.ly/2gR2woJ (login as ‘guest’, university, or openOLAT account)
MAINZ Award 2015 granted to Dr. Sven Bach and Dr. Antonia Statt
Every year the MAINZ Award is granted for two outstanding PhD theses. Former PhD students who achieve a degree "with distinction" (summa cum laude) and manage to complete the MAINZ certifivate are candidates for nomination by their supervisors. ...
Graduate School of Excellence MAINZ awards visiting professorships 2016
MAINZ Visiting Professorships awarded to Egbert Willem Meijer (left) and Gen Tatara (right)
The Graduate School of Excellence "Materials Science in Mainz" (MAINZ) has again awarded visiting professorships to two outstanding scientists. The MAINZ Visiting Professorships 2016 were presented at a gala event on Monday evening to Professor Egbert Willem Meijer, a chemist of Eindhoven Technical University in the Netherlands and to Dr. Gen Tatara, a theoretical physicist of the Japanese research institute RIKEN. Visiting professorships are a way to attract foreign scientists to the various departments of the MAINZ Graduate School so they can do part of their research here as well as work with the doctoral candidates studying at MAINZ. Their input can take the form of lectures, seminars, and workshops that help in training doctoral candidates at MAINZ. The visiting professorships have been awarded annually since 2013 to a maximum of two scientists.
Egbert Willem Meijer is one of the world’s leading scientists in the field of supramolecular chemistry. His research on functional supramolecular polymers has even resulted in a new class of materials. His work on supramolecular polymers, i.e., supra-structures consisting of self-organizing molecules, has also made them interesting from a technological viewpoint, all the more so since Meijer successfully achieved unanticipated material properties. Meijer is Scientific Director of the Institute for Complex Molecular Systems at Eindhoven Technical University. He has received numerous awards and visiting professorships for his work, among them the 2001 Spinoza Award, the highest scientific award in the Netherlands. Besides intensifying scientific collaborations, the chemist will offer MAINZ doctoral candidates an opportunity to participate in a master class in supramolecular chemistry.
Dr. Gen Tatara heads a department for theoretical physics at the RIKEN research institute in Japan. He works in spin physics, a field of research with a focus on the intrinsic angular momentum of electrons. Tatara’s particular emphasis is on the reciprocal effect between spin currents and magnetization in condensed matter. He has made pivotal contributions to the theoretical description of the dynamics of domain walls. As a visiting professor in Mainz, he will not only forge contacts with scientists in the field of theoretical physics, but also intensify his connections to experimental groups with whom he has in part already published. In particular, the Japanese scientist will offer doctoral candidates at the MAINZ Graduate School an opportunity to participate in courses on theoretical methods in spintronics. ...
MAINZ Alumnus Eberhard Jakobi named in Capital magazine's "40 under 40"
Eberhard Jakobi is one of the “40 under 40” that Capital magazine has, for the ninth time since 2007, selected across German business, politics and society as part of its “Young Elite” project. The categories included entrepreneurs, managers, politics and state and society. Eberhard has graduated from MAINZ in 2010. ...
MAINZ-Alumnus Helmut Schultheiß receives national award for solid state physics
Helmut Schultheiß, who earned his Ph.D. in the group of Burkard Hillebrands at the University of Kaiserslautern will be awarded the Walter Schottky Prize 2017 of the German Physical Society (Deutsche Physikalische Gesellschaft, DPG). He receives this prestigious award for his fundamental research about spin wave propagation in nano structures and their application in new functional devices for transport and logic processing of information. After doing a postdoc at Argonne National Laboratory, Helmut is now heading an Emmy Noether research group at the Helmholtz-Zentrum Dresden-Rossendorf. ...
Funding for MaHoJeRo exchange project with Tohoku University (Sendai, Japan) and Seoul National University (Seoul, Korea) granted by DAAD
DAAD is funding a new exchange program with Tohoku University (TU), Sendai, Japan and Seoul National University (SNU), Seoul, Korea. 'MaHoJeRo: Rotating spins and young scientists for GreenIT devices' will support exchange of students and staff of JGU, TU, and SNU to train and work on revolutionary technologies in the field of spintronics tackling the key societal challenge of low power information technology. Within MaHaJeRo targeted, collaborative actions, such as joint workshops and student exchanges, will become part of an efficient international research effort and will contribute to the ‘MAINZ goes Asia’ strategy. Skills education and management strategy will be taught both through courses and ‘on the job’ to achieve the scientific goals, provide comprehensive training of students and facilitate the transfer of knowledge through visits and secondments of students and staff.
MAINZ PI Burkard Hillebrands recently appointed as Scientific Director of the Leibniz Institute for Solid State and Materials Research (IFW) in Dresden
The Physicist will also continue his research at the TU KL where he heads the research group „Magnetism“. His main research interest is directed towards the properties and applications of magnons and the material properties of magnetic nano systems. ...
MAINZ Associated Member Priv.-Doz. Dr. Frederik Wurm receives Reimund Stadler Award 2016
With the Reimund Stadler Award 2016, the German Chemical Society (GDCh) recognizes the junior scientist Priv.-Doz. Dr. Frederik Wurm for his research on the synthesis of phosphorus-containing polymers and their interaction with biomaterials. ...
MAINZ Principal Investigator Prof. Dr. Klaus Müllen receives Hermann Staudinger Award 2016
The emeritus director of the Max Planck Institute for Polymer Research (MPI-P) and current Fellow of the Gutenberg Research College (GRC), Prof. Dr. Klaus Müllen, receives the award of the German Chemical Society (GDCh), endowed with a gold medal and prize money. The Hermann Staudinger Award honors the scientist for his research on the synthesis of polycyclic aromatic hydrocarbons and 2D macromolecules for electronic components. ...
International team of scientists including MAINZ PhD Joel Cramer, MAINZ Alumni Dr. Andreas Kehlberger and MAINZ PIs Prof. Gerhard Jakob and Prof. Mathias Kläui unveils fundamental properties of spin Seebeck effect
Direct correlation between temperature dependent generation of spin currents and atomic composition of interfaces found ...
MAINZ PhD student Kristina Klinker wins the Advanced Healthcare Materials prize at the 11th International Symposium on Polymer Therapeutics (Valencia, Spain)
The Advanced Healthcare Materials prize for the best oral presentation was awarded to Kristina Klinker for her talk on Adjusting Functionality of Core Cross-Linked Nanostructures based on Reactive Polypept(o)ides. ...
MAINZ-based physicists Sebastian Golde, Thomas Palberg and collegues find missing link between glass formation and crystallization
Densified regions with drastically reduced internal motion either act as crystal precursors or cluster and frustrate all further dynamics
Glasses are neither fluids nor crystals. They are amorphous solids and one of the big puzzles in condensed matter physics. For decades, the question of how glass forms has been a matter of controversy. Is it because some regions freeze their thermal motion? Or is it because there are particles or clusters which do not fit to form a crystal? At least for the model system of hard spheres, researchers at Johannes Gutenberg University Mainz (JGU) have now taken a major leap in reconciling these two opposing views. Using a clever combination of light scattering and microscopy, they were able to demonstrate that within a melt of hard spheres small compacted regions form comprising a few hundred spheres. These so-called precursors are the starting point for both crystallization at moderate undercooling and glass formation at large undercooling. The researchers observed that the motility of particles within these precursors was extremely limited and decreased further with undercooling, while their number rapidly increased. With only few precursors present, crystallization may still start at the surface. However, the more of these precursors are present, the more of their surface they block. Moreover, with the precursor number still increasing in time, the system soon gets jammed and all further dynamics cease. This means that from a certain point in undercooling and time onwards, crystal formation is no longer possible. The results of this research work performed in the JGU Graduate School of Excellence "Materials Science in Mainz" (MAINZ) have recently been published in the journal Nature Physics as an advanced online publication.
Glass and crystal are two different structures but either of these can form from a melt. In the case of glass, the atoms retain their disorganized state, similar to that seen in liquids, while in crystals they assume a very regular lattice structure. It is the solidification process that determines which type of structure will be formed. The physics experiments carried out at Mainz University did not focus on the fabrication of a particular glass, such as for use in safety windows or fiber optics for communication purposes. They were rather aimed at an advanced understanding of the glass formation process in general, which is a traditional research topic in the JGU Condensed Matter Physics group. The researchers were looking at the formation of amorphous solids in general, and they used an experimental model system for hard spheres. Here the undercooling is not realized by decreasing the temperature, but by increasing the concentration of polymer spheres. Crystals form when more than 50 percent of the volume is taken by the hard spheres in the suspension, while glasses form at more than 60 percent. Such systems of micro-sized polymer spheres in a solvent have been subject to intense research over the last decades, because they closely mimic the behavior of ideal hard spheres which are well studied by theory and computer simulation.
It has been known since the 1990s that hard-sphere melts contain both regions of differing density and order as well as regions that vary in terms of the motility of the atoms, i.e., regions of structural and dynamic inhomogeneity. Since then, the role played by these two factors during the process of solidification has been the subject of intense debate by theoretical physicists. "What we have now ascertained is that these regions are in fact identical, thus laying the controversy to rest," said Professor Thomas Palberg of the Institute of Physics at Mainz University, explaining the results of his research.
Mapping motility within hard-sphere suspensions
In order to understand the processes taking place, Sebastian Golde, a member of the MAINZ Graduate School of Excellence and Palberg's research team, investigated hard-sphere model systems in an optical experiment. "We were able to show that the regions with more densely packed spheres and a little more order coincide with those areas where the hard spheres clearly move more slowly," stated Golde. This means that the long-standing enigma concerning the two different regions of inhomogeneity has been resolved.
The method used is a combination of static and dynamic light scattering. "We analyze how much light of a laser beam directed at the sample is scattered in a given direction. This tells us the sample structure. But we also analyze how it flickers after scattering. This tells us how fast the particles move," said Golde, who himself built his instrument designed by Dr. Hans Joachim Schöpe, who recently moved to the University of Tübingen. Moreover, utilizing a clever imaging system, Golde was able to obtain so-called dynamic maps with unprecedented resolution somewhat smaller than the precursors. Like an image produced by a camera, the result is a kind of photo that captures the activity of the dynamics within the various regions. Thus, the researchers observed that as time proceeded, ever more small dense areas with slow-moving spheres were generated. Their formation speed decides whether there is enough time left for the formation of crystals before jamming occurrs. Since the precursor formation speed is related to the hard-sphere concentration, one finds crystallization at low concentrations of hard spheres. On the other hand, at higher concentrations these compacted regions become quickly arrested and the system solidifies into a glass.
"In other words, glass results when so many crystallization precursors are formed that they in effect arrest each other," clarified Palberg. "For us, this means that an unexpected and fascinating link has been found between the two solidification scenarios. Arguably, this was one of the most important missing pieces of the puzzle." The findings are believed to be very general, but the investigation should clearly be extended also to other model systems to further support the view of coinciding structural and dynamical inhomogeneities being responsible for glass formation. ...
Multifunctional molecular materials -- bridging magnetism and luminescence
The present project focuses on molecular materials that unite the key properties of magnetism and luminescence. This property combination is still an exception today as paramagnetism diminishes luminescence usually. However, a successful implementation of both properties in one compound allows for materials properties that emerge from the influence of magnetism on luminescence and vice versa. Thereby, the project has the aim to develop a novel sensing type benefitting from this property dependence. ...
New collaborative research center in quantum physics
"OSCAR-Open System Control of Atomic and Photonic Matter" is a new transregional CRC associated with MAINZ. Within OSCAR, Kaiserslautern physicists, together with colleagues from the University of Bonn, will explore the new physics of open quantum systems in model systems such as atoms, ultra-cold quantum gases and photons.
OSCAR combines the collaborative efforts of theoretical and experimental groups with complementary expertise in few- and many-body physics, photonics and ultra-cold atom physics. OSCAR’s goal is to explore the novel physics of open systems, i.e. the physics resulting from time-dependent drive and coupling to tailored reservoirs across different experimental platforms. This comprises the generation of otherwise unreachable quantum states, their protection, and the control of dynamical and transport processes. The researchers aim to understand the underlying mechanisms of open systems and to exploit them as new tools for quantum control. To this end, they will also combine open-system control and topological protection.
The physical realizations of choice are atoms and photons for which the technology of manipulation and detection are most advanced and microscopic control and understanding of system and environment is possible. Open-system control is a versatile concept and the teams involved expect that the insights gained will open up new avenues for applications in technology and new device functionalities.
OSCAR will be funded by the Deutsche Forschungsgemeinschaft (DFG) with a total of 9.4 million euros and will start July 2016. In the first four-year funding period, the collaborative research center is coordinated by the University of Bonn. Hereafter, a transfer of the coordination to Kaiserslautern is planned. OSCAR is the fifth collaborative research center at the Kaiserslautern physics department. The center is embedded in the State Research Center "OPTIMAS" and was only made possible through this funding of the State Rhineland-Palatinate.
Four MAINZ Alumni awarded at JGU’s Dies Academicus 2016
MAINZ Associated Member Jun.-Prof. Dr. Matteo Rizzi has been nominated "APS Outstanding Referee" by the American Physical Society
The Outstanding Referee program recognizes scientists who have been exceptionally helpful in assessing manuscripts. The referees’ efforts keep the standards of journals at a high level and help authors to improve the quality of their articles. ...
MAINZ PhD students Hagen Söngen (AK Kühnle) and Sven Otto (AK Heinze) are among the new members of the Gutenberg Academy for Young Researchers.
Excellence@WORK - Gutenberg Alumni Talks in Natural Sciences: new lunch talk series supported by GNK
Excellence@WORK offers personal insights into a broad range of scientists‘ careers. It illustrates job perspectives for young scientists relying on Gutenberg Alumni as role models and trustful advisors.
Alumnae and alumni report on
- individual careers in IT, manufacturing, microelectronic, pharmaceutical and chemical industry, consulting, NGOs or public institutions
area of operations, career paths, success factors, helpful personal competences and skills, job perspectives and the relevance of their studies and doctoral education
We thus take advantage of the JGU alumni network for (doctoral) students from natural sciences at JGU, IMB, MPI-C and MPI-P. Students gain personal insights into daily routine and career paths of alumni and profit for their personal career planning.
Please note that these talks will be conducted in German. ...
European Research Council (ERC) Advanced Grant for MAINZ PI Burkard Hillebrands: Supercurrents with magnons - the basis for future data processing technologies
The Grant of the European Research Council (ERC) for the Physicist from the University of Kaiserslautern is endowed with more than 2.4 million euros.
With the ERC funding Hillebrands will open up a new field of research: supermagnonics. He and his team will investigate macroscopic magnonic quantum phenomena with the aim to make data processing significantly more efficient. The award-winning concept is an advancement of magnonics – a field which was already fundamentally co-developed by Hillebrands. It is based on magnetic phenomena in crystal lattices that are caused by the spin, or intrinsic angular momentum, of electrons. Immaterial spin waves (known as magnons) serve as a medium and carrier of information. As waves are able to transmit more information than electrons and heat generation can be kept to a minimum, this creates completely new means of making data processing substantially more efficient. One day this may lead to new systems of computer technology.
Quantum phenomena on a macroscopic scale
With his supermagnonic research, Professor Hillebrands seeks to take the field of magnonics a critical step forwards. “We want to study phenomena that are analogous to superconductivity with electrons or to superfluidity in super-cooled liquid helium, i.e. phenomena which have macroscopic dimensions,” the researcher explains. “Quantum effects are usually only observed at an atomic or subatomic scale.”
In previous experiments he and his team have already demonstrated that magnons can form what is known as a Bose-Einstein condensate (BEC). This is a special type of matter which is characterised by the fact that all the particles (in this case magnons) adopt an identical, precisely defined basic state. By manipulating this condensate accordingly, it is possible to trigger magnonic supercurrents that flow without any loss of energy – these can be applied for information processing.
Over the next five years, Burkard Hillebrands intends to use the ERC grant to explore the basic mechanisms behind supermagnonics. In doing so, he will benefit from his many years of experience as a pioneer of magnonics. “In my team that belongs to the State Research Center OPTIMAS, we have developed the diagnostic tool of Brillouin spectroscopy over the course of many years. This is now proving to be invaluable to us”, emphasizes the experimental physicist. “In simple terms, it enables us to analyze the magnonic processes within the magnetic crystal films by way of scattering laser light.” The research planned by Hillebrands is complemented ideally by the ERC Starting Grant recently awarded to his co-worker Dr Andrii Chumak for advancing the technological aspects of magnonics.
Excellent research achievement
Every year the European Research Council awards funding in the form of the ‘ERC Advanced Grant’ amounting to up to 2.5 million euros per research project to established scientists who are leading in the respective field of research. It is hence the European Union’s most important scientific prize. It is granted to internationally recognized top researchers who have gained attention for their outstanding achievements and ground-breaking project ideas. The fact that one of these awards has now been conferred to Professor Hillebrands shows the increasing significance of the field of magnonics. “We do not just see the award as a personal accolade,” the researcher notes, “but also as motivation for the whole team who will carry on the successful research with huge determination.”
The first aim will be the development of robust laboratory methods that can be used to create magnonic supercurrents in BECs. A key aspect of this is to learn how these supercurrents can be controlled by electrical fields. “This is absolutely pioneering work,” the physicist points out, “here we are working with high risks, but the gains also stand to be huge. This may even mean that our research findings might open up completely different and unexpected opportunities.” ...
PhD Award of the German Physical Society to MAINZ-Alumnus Fabian Grusdt
During the recent Spring Meeting of the German Physical Society (Deutsche Physikalische Gesellschaft, DPG) – Section Atoms, Molecules, Quantum optics and Plasmas (SAMOP), Fabian Grusdt (now Harvard) was awarded the PhD Prize 2016. In a final round of scientific oral presentations Fabian Grusdt achieved the Award amongst three competitors. The Award renders him to „Germany’s best Ph.D. Student” of the AMOP section the second largest section of DPG. Fabian Grusdt did his Ph.D. in the group of Michael Fleischhauer (Department of Physics, TU Kaiserslautern) and finished it last year at the young age of 24. In the meantime he is a postoc at Harvard University, again in a very prestigious framework – he was awarded a fellowship of the Moore Foundation that provides him with a 3-year independent research stay.
In his Ph.D. thesis „Topological phases and polaron physics in ultracold quantum gases“ Fabian Grusdt has made important contributions to two research topics of very high interest in many body physics and quantum optics – systems of topological order and the physics of Bose polarons. For the first time, he provided a generalization of the bulk-boundary correspondence principle that is crucial for topological systems to interacting bosons.
Moreover, he has developed new detection methods for Z2 topological invariants and topological invariants of interacting systems. An important part of his dissertation focussed on one of the oldest but still not fully understood problems in condensed matter: Bose polarons.
For this, Fabian Grusdt developed a completely new theoretical approach based on the renormalization group which has lead to first semi-analytical theory of Fröhlich polarons in the whole range of interaction strengths. The community considers his all-coupling theory of Fröhlich polarons as a very important finding.
Excellent teaching builds on excellent research: MAINZ PI Artur Widera receives Teaching Award
The Rhineland-Palatinate teaching award of the Ministry of Education, Science, and Culture (MBWWK) was recently awarded to MAINZ faculty member Artur Widera of the University of Kaiserslautern. This award is part of the higher education program "Wissen schafft Zukunft" (science for future) and is given within ten academic disciplines. Each award is endowed with 10.000 €
"I am very glad about this award, because teaching is really on my heart. For me, good teaching comes from good research and I really enjoy to develop new methods and applications with my students in order to better introduce them to the subject" explains Artur Widera. In 2010, Widera came to the University of Kaiserslautern from the University of Bonn. He does research and teaching in quantum physics in ultracold matter in order to understand quantum phenomena at single atoms at temperatures below that in space. For Widera this is not the first award. In 2013 he was awarded the University Teaching Award for the use of voting tools in teaching. In 2011, he received an ERC Starting Grant, the most prestigious European Research Award.
International research team achieves controlled movement of skyrmions
A joint research project being undertaken by Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) has achieved a breakthrough in fundamental research in the field of potential future data storage technologies. The idea is that electronic storage units (bits) will not be stored on rotating hard disks as is currently standard practice but on a nanowire in the form of magnetic vortex structures—so-called skyrmions—, using a process similar to that of a shift register. The magnetic skyrmion bits would be rapidly accessible, while storage density would be high and there would be improved energy efficiency. The project team managed, for the first time, to achieve targeted shifting of individual skyrmions at room temperature using electrical impulses. Their results have been published in the journal Nature Materials.
Magnetic skyrmions are special spin configurations that can occur in materials and particularly in thin layer structures when the inversion symmetry is broken. With regard to the systems that are of interest here, this means that a thin metal film with a non-symmetrical layer structure can be employed. In materials such as this, spin configurations that behave rather like a hair whorl can form. It can be just as difficult to eradicate a skyrmion as it can be to smooth out a hair whorl, a property that gives skyrmions enhanced stability.
An important characteristic of skyrmions is that they can exist in isolation in magnetic materials and generally do not tend to collide with the edge of a structure. This provides them with the unique ability to skirt any isolated defects or unevenness in the material with which other magnetic structures, such as domain walls, would collide. Skyrmions are therefore excellent candidates for use with magnetic shift registers, otherwise known as racetrack memory. Information could be encoded in the form of skyrmions and an electrical current could be employed to move them past fixed read/write heads. The process would be both rapid and completely independent of movable mechanical components and thus ideally suited for mobile applications.
During the project, it was demonstrated that individual skyrmions can indeed be moved in a controlled manner along a magnetic wire, i.e., the so-called racetrack, by exposing them to brief electrical impulses at room temperature. In addition, new methods to describe their dynamics were developed and confirmed by experimentation. This work can thus be regarded as laying down the cornerstone for the future use of skyrmions in application-related systems.
"It is always great to see when a joint project quickly leads to exciting results. This is particularly true in this case, as we have been able to produce this journal article within just a year of entering into our cooperation agreement. It would never have come about had it not been for the close collaboration between Mainz University and MIT and the lively exchange of ideas," said Kai Litzius, co-author of the article. Litzius is on a stipendiary scholarship awarded by the Graduate School of Excellence "Materials Science in Mainz" (MAINZ) and is a member of the team headed by Professor Mathias Kläui.
"I'm delighted by the way we were able to work efficiently and continuously with groups at MIT. After receiving start-up funding through a joint project financed by the German Federal Ministry of Education and Research, we have been able to produce six joint publications since 2014, partly as the result of several student visits to MIT," emphasized Kläui, a professor at the Institute of Physics and the director of the MAINZ Graduate School of Excellence.
Establishment of the MAINZ Graduate School was approved through the Excellence Initiative by the German Federal and State Governments to Promote Science and Research at German Universities in 2007 and its funding was extended in the second round in 2012. It consists of work groups from Johannes Gutenberg University Mainz, TU Kaiserslautern, and the Max Planck Institute for Polymer Research in Mainz. One of its focal research areas is spintronics, where cooperation with leading international partners plays an important role.
Seonghoon Woo et al.
Observation of room-temperature magnetic skyrmions and their current-driven dynamics in ultrathin metallic ferromagnets
Nature Materials, 29 February 2016
DOI: 10.1038/nmat4593 ...
Spin waves out of waste heat: Researchers present new findings on magnetic spin waves
Spin waves, or magnons, are fundamental excitations in magnetic materials which transport energy and angular momentum. The latter allows to make use of them for the transmission of information within magnetic solids. Since their existence is bound to that of magnetic solids, they are challenging to measure. This circumstance led to quite a number of difficulties with respect to the proof of fundamental theories about the properties of magnetic materials. In a joined project, the researchers involved were able to show that even in complex systems consisting of many different magnetic atoms, magnons can be thermally excited by making use of the recently understood spin Seebeck effect. These results furthermore show that the spin Seebeck effect can be employed to probe fundamental properties of such systems in a simple way and thus to deduce the complex interplay of the constituents.
The spin Seebeck effect represents a so-called spin-thermoelectric effect, which enables the conversion of thermal energy into electrical energy. Contrary to conventional thermoelectric effects, it also enables the recovery of heat energy in magnetic insulators in combination with a thin metallic layer. Researchers at Mainz University have recently been able to demonstrate that the origin of the spin Seebeck effect can be understood as thermally excited spin waves within the magnetic solid. These thermal spin waves present a so far unexploited way for the energy recovery of waste heat.
Following this discovery, the researchers started investigations of more complex materials, so called ferrimagnets. In contrast to simple ferromagnetic materials, ferrimagnets possess a non-trivial temperature dependence of the magnetization, resulting of a complex interplay of its different magnetic sublattices. By making use of temperature dependent spin Seebeck measurements of ferrimagnetic materials, it was possible to deduce characteristic and thus unique signal features. These features can be traced back to the magnonic origin of the effect and therefore allow to gain a new idea of thermal magnons and their distribution.
Stephan Geprägs, A. Kehlberger, F. Della Colleta, et al.
Nature Communications 7, Article number: 10452, Published 04 February 2016
Klaus Müllen becomes a new Gutenberg Research Fellow
In recognition of his scientific achievements, Professor Dr. Klaus Müllen, emeritus director at the Max-Planck Institute for Polymer Research in Mainz, Germany, has been appointed by the President of the Johannes Gutenberg University (JGU) as a Gutenberg Research Fellow for a period of three years. The ceremony will take place in the “Hochschule für Musik” on May 2 during the Gutenberg Research College (GRC) annual ceremony.
The GRC fellowship assures each fellow first class research conditions. It is generously endowed. Funds for academic personnel as well as for material expenses are available. The GRC fellows are expected to offer their expertise to young academics – for example with Research Training Groups or the Gutenberg Academy. In the long term, the fellows contribute to the elaboration of perspectives and strategies concerning the future development of the Johannes Gutenberg University.
The GRC, established in 2007, serves as a central strategic instrument to promote cutting-edge research at JGU. The GRC runs an annual budget of €2 million, provided in equal parts by the State and by JGU. ...
MAINZ Associated Member Dr. Frederik Wurm nominated for the Reimund Stadler prize
Dr. Frederik Wurm was nominated on September 29 for his research and the associated talk he gave on "Poly(phosphoester)s: from adhesives to polymer therapeutics". He will be awarded the Reimund Stadler prize - endowed with € 5,000 - in Halle in the autumn 2016. Exceptionally this year, during the postdoctoral workshop of the GDCh division of Macromolecular Chemistry held at the Lanxess production site, in Leverkusen the jury selected two winners. ...
MAINZ PhD Christoph Kreitner (group of Prof. Heinze) publishes a cover article in the journal Inorganic Chemistry 2015
In the publication „Understanding the Excited State Behavior of Cyclometalated Bis(tridentate)ruthenium(II) Complexes: A Combined Experimental and Theoretical Study”, published in Inorganic Chemistry in 2015, Christoph Kreitner of the group of Katja Heinze tackles two fundamental questions concerning a promising class of bis(tridentate)ruthenium(II) complexes incorporating a cyclometalating N^C^N and a terpyridine N^N^N ligand.
First, in contrast to common belief in the literature, they demonstrated by Resonance Raman Spectroscopy and density functional calculations that both ligands contribute to the prominent visible range absorption features. Second, the unexpected poor emission quantum yields of these complexes is traced back to a previously unrecognized dark LL’CT state which provides a parasitic pathway for the deactivation of the emissive excited state. The importance of these results was highlighted as a cover article in the December issue of Inorganic Chemistry. ...
Prof. Katharina Landfester has become a member of the Board of the German Chemical Society
New Collaborative Research Center for Spin Phenomena
A team of researchers including MAINZ PhD Hannah Pohlit developed a more easily tolerable method for the treatment of allergies
Allergen-specific immunotherapy (SIT) is the only available cause-oriented therapy for allergies so far. In their publication the authors introduce a method to encapsulate allergens into nanoparticles to avoid severe side effects during SIT.
DOI: 10.1021/acs.biomac.5b00458 ...
MAINZ Award 2014 granted to Dr. Markus Bannwarth and Dr. Isabel Schick
Every year the MAINZ Award is granted for two outstanding PhD theses. Former PhD students who achieve a degree "with distinction" (summa cum laude) and manage to complete the MAINZ certifivate are candidates for nomination by their supervisors.
The recipients of the MAINZ Award 2014 are Dr. Markus Bannwarth (right) and Dr. Isabel Schick (left). ...
MAINZ Graduate School of Excellence awards Visiting Professorships 2015
Oxford theoretical physicist Dieter Jaksch and spintronics expert Thierry Valet have been awarded MAINZ Visiting Professorships
The Graduate School of Excellence "Materials Science in Mainz" (MAINZ) has awarded the 2015 MAINZ Visiting Professorships to two European researchers. The Visiting Professorships went to Professor Dieter Jaksch (on the left) of the University of Oxford, England, and Thierry Valet (on the right) from France. Visiting Professorships are used to attract foreign scientists to the various departments of the MAINZ Graduate School so that they undertake part of their research here and on this occasion work with the doctoral candidates studying at MAINZ. The Visiting Professorships have been awarded to up to two winners each year since 2013. The award winners are invited to spend up to twelve months working at MAINZ during a two year period. Their input can take the form of lectures, workshops, or other contributions which help the training of doctoral candidates. They thus provide important new educational stimuli and in turn help establish a relationship between MAINZ and their home universities. ...
MAINZ PhD Student Hannah Pohlit is one of the two very first awardees of the ALK "Förderpreis Allergologie"
This year, the pharmaceutical company ALK-Abelló donated for the first time, in cooperation with the German association for allergology and clinical immunology (GDGAKI), the association for pediatric allergology and environmental medicine (GPA) and the association of German allergists (AeDA), a development award for allergology. The prize, endowed with 30.000 EUR, has been awarded to Hannah Pohlit, JGU Mainz, and Georg Bölke, Charité Berlin.
(Picture: © Anke Sinnigen, ALK-Abelló) ...
MAINZ PhD Student Moritz Barkowski wins second prize in the poster session of the CECAM Workshop in Lausanne
MAINZ PhD student Moritz Barkowski won the second prize in the poster session with the title "Depth-dependent study of femtosecond spin-currents in Ni/Au" of the CECAM Workshop "Exploration of ultra-fast timescales using time dependent density functional theory and quantum optimal control theory in Lausanne, Switzerland.
M. Barkowski, O. Schmitt, J. Urbancic, S. Eich, J. Mao, S. Sadashivaiah,
D. Steil, M. Cinchetti, S. Mathias, and M. Aeschlimann
Publication by MAINZ PhD Students Sven Otto and Christoph Kreitner highlighted as Hot Paper in Angewandte Chemie
Intelligent ligand design, increasing the ligand field splitting beyond the usual regime for chromium(III) complexes made these outstanding properties possible. Such large ligand field splitting for chromium(III) is otherwise only known from the solid material ruby, where it is used in the important solid state ruby laser. The molecular complex further exhibits superior stability in solution over a long time and under irradiation as well and does not oxidatively damage biological material under irradiation. These properties, together with the simple synthesis, make [Cr(ddpd)2]3+ very promising as an inexpensive alternative to currently employed materials based on rare earth metals for biological applications like in vivo oxygen sensing.
S. Otto, M. Grabolle, C. Förster, C. Kreitner, U. Resch-Genger*, K. Heinze*, Angew. Chem. 2015, 127, 11735–11739; Angew. Chem. Int. Ed. 2015, 54, 11572-11576
[DOI: 10.1002/anie.201504894] [DOI: 10.1002/ange.201504894] ...
MAINZ at “Wissenschaftsmarkt 2015”
MAINZ has participated at the “Wissenschaftsmarkt 2015” with interesting and sometimes amazing applications from the world of materials. Experiments and exponents from Chemistry, Optics, and Quantum Physics have been presented: Secure explosives samples for search dogs; Who can smell better?; Optical light fibers to touch; Playing with interference of light; Laser Spectroscopy: understanding and controlling atoms; and ‘A refrigerator by light for temperatures close to absolute zero - matter on the way in the quantum world’ by research groups from Mainz (Prof. Waldvogel lab) and Kaiserslautern (Profs. Ott and Widera labs). This public-science-dialog had plenty of opportunities. For the visitor to observe live experiments and ask questions; and for the scientists to listen, reflect and gather impulses, making it an interesting, informative, fun event for all.
(Picture: © Barbara Walzer)
Greenhorn Meeting 2015
The recent “Greenhorn Meeting” at the Department of Physics of the University of Kaiserslautern brought together young researchers from quantum optics, atom optics and experimental quantum physics. The participants, bachelor and master students, as well as PhD students, came from all over Germany, Denmark and Austria. They presented their research projects in posters and lectures und discussed about them in a casual atmosphere. Kaiserslautern made favorable impressions on all guests not only for its own research in the area of quantum optics but also for the attractive social program. An excursion to Hambach Castle and the conference dinner at a traditional Kaiserslautern restaurant, including new wine, was very well received. The conference was organized by MAINZ PhD student Felix Schmidt and his colleague Tobias Lausch from the research group of Professor Artur Widera.
Financial support was provided by the State Research center OPTIMAS, by MAINZ and by the collaborative research program SFB/TRR 49. Also several laser companies made generous financial contributions. ...
Indications of the origin of the Spin Seebeck effect discovered
Thermally excited magnetic waves enable generation of electricity using insulators
The recovery of waste heat in all kinds of processes poses one of the main challenges of our time to making established processes more energy-efficient and thus more environmentally friendly. The Spin Seebeck effect (SSE) is a novel, only rudimentarily understood effect, which allows for the conversion of a heat flux into electrical energy, even in electrically non-conducting materials. A team of physicists at Johannes Gutenberg University Mainz (JGU), the University of Konstanz, the University of Kaiserslautern, and the Massachusetts Institute of Technology (MIT) have now succeeded in identifying the origin of the Spin Seebeck effect. By the specific investigation of the material- and temperature-dependence of the effect, the German and American researchers were able to show that it exhibits a characteristic length scale attributable to its magnetic origin. This finding now allows for the advancement of this long-time controversial effect in terms of first applications. The resulting research paper was published in the scientific journal Physical Review Letters, with a fellow of the JGU-based Graduate School of Excellence "Materials Science in Mainz" (MAINZ) as first author.
The Spin Seebeck effect represents a so-called spin-thermoelectric effect, which enables the conversion of thermal energy into electrical energy. Contrary to conventional thermoelectric effects it also enables the recovery of heat energy in magnetic insulators in combination with a thin metallic layer. Owing to this characteristic, it was assumed that the effect originates from thermally excited magnetic waves. The currently employed method of measurement, which makes use of a second metallic layer converting these magnetic waves into a measurable electrical signal, has so far not been able to allow for a distinct assignment of experimentally detected signals.
By measuring the effect for different material thicknesses in the range of a few nanometers up to several micrometers as well as for different temperatures, the scientists have found characteristic behavior. In thin films the signal amplitude increases with increasing material thickness and eventually saturates after exceeding a sufficient thickness. In combination with the detected enhancement of this critical thickness at low temperatures, the agreement with the theoretical model of thermally excited magnetic waves developed at Konstanz could be demonstrated. With these results, the researchers were able for the first time to reveal a direct relation between the assumed thermally excited magnetic waves and the effect.
"This result provides us with an important building block of the puzzle of the comprehension of this new, complex effect, unambiguously demonstrating its existence," said Andreas Kehlberger, Ph.D. student at Johannes Gutenberg University Mainz and first author of the publication.
"I am very pleased that this exciting result emerged in a cooperation of a doctoral candidate out of my group at the Graduate School of Excellence 'Materials Science in Mainz' together with co-workers from Kaiserslautern and our colleagues from Konstanz, with whom we collaborate within the Priority Program 'Spin Caloric Transport' funded by the German Research Foundation (DFG)," emphasized Professor Mathias Kläui, director of the MAINZ Graduate School of Excellence based at Mainz University. "It shows that complex research is only possible in teams, for instance with funding by the German Federal Ministry of Education and Research (BMBF) through the Mainz-MIT Seed Fund."
Kehlberger, A. et al.
Length Scale of the Spin Seebeck Effect
Physical Review Letters, 28. August 2015
DOI: 10.1103/PhysRevLett.115.096602 ...
Poster awards to MAINZ Ph.D. student Dmytro Bozhko
Together with his co-authors, 2nd year Ph.D. student Dmytro Bozhko from TU Kaiserslautern was awarded these two prestigious poster awards recently:
- Gold Poster Award at the 8th IEEE Magnetics Society Summer School 2015 (Minneapolis, USA, June 14-19, 2015) for poster "Spin pumping by Bose-Einstein condensate of magnons in YIG/Pt bilayers" by D.A. Bozhko, A. Kirihara, Y. Tserkovnyak, A.V. Chumak, B. Hillebrands and A.A. Serga, presented.
- Best Poster Award of Monday's Session of the 20th International conference on Magnetism (ICM 2015; Barcelona, July 5-10, 2015) for poster "Stimulated thermalization of a parametrically driven magnon gas as a prerequisite for Bose-Einstein magnon condensation" by D.A. Bozhko, P. Clausen, V.I. Vasyuchka, B. Hillebrands, G.A. Melkov, and A.A. Serga.
Carl Zeiss Foundation donates EUR 850,000 to the Advanced Lab for Electrochemistry and Electroorganic Synthesis at Mainz University
Research structure concept of ELYSION enhances the strategic relevance of Mainz in the fields of electroconversion and electroactive materials
Over the next four years, the Carl Zeiss Foundation will be providing support in the form of EUR 850,000 to the Advanced Lab for Electrochemistry and Electroorganic Synthesis (ELYSION), a unique collaborative research concept based at the Institute of Organic Chemistry and the Institute of Inorganic Chemistry and Analytical Chemistry at Johannes Gutenberg University Mainz (JGU). The use of electricity as a catalyst in chemical reactions is one of the most sustainable methods of synthesizing materials and chemical compounds. The accompanying development of electrolytic conversion techniques and new types of electrodes will make it possible to overcome the existing frontiers of this future-oriented approach. ...
Ana Fokina has been awarded a Journal of Materials Chemistry C runner up Poster Prize
Article on "Thermodynmaic picture of ultrafast charge transport in graphene", co-authored by the MAINZ Faculty members Prof. Müllen, Prof. Bonn and Prof. Turchinovich, published in Nature Communications
Greta Becker won the Poster Award at the IP'15- International Symposium on Ionic Polymerization on July 05-10, 2015
Prof. Klaus Müllen – the most cited German scientist in chemistry – is awarded a new honorary degree
Publications Highlight in Nature Physics, Giant magnetoresistance systems examined by means of ultrafast terahertz spectroscopy
Three MAINZ Alumni awarded at JGU’s Dies Academicus 2015
TRR 49 funding extended
Hai Wang Receives Prestigious Chinese Government Award for Outstanding Self-Financed Students Abroad
Hai Wang, a PhD student in the department of Molecular Spectroscopy at MPIP has been awarded with the "2014/15 Chinese Government Award for Outstanding Self-Financed Students Abroad". This prestigious prize, sponsored by the Chinese Ministry of Education, recognizes the academic excellence of self-financed Chinese students studying overseas, being granted yearly across all research disciplines among more than 30000 students in Germany. Hai Wang received the prize from the Chinese ambassador, Mr. Shi Mingde, in a ceremony that was held in Berlin on 9th of May, 2015.
Since January 2012, Hai is a student within the "Graduate School of Excellence – Materials Science in Mainz” at the Johannes Gutenberg University in Mainz. Together with Dr. Enrique Canovas and Prof. dr. Mischa Bonn, Hai's work have been devoted to the characterization and modelling of photo-induced electron transfer processes at hybrid interfaces, which are relevant for novel low cost energy conversion schemes (solar cells and fuels). Hai has demonstrated the tunneling nature of bridge mediated charge transfer in quantum dot sensitized architectures1; the suitability of atomic passivation of QDs by fine tuning of surface chemistry by stoichiometry control2; and, in collaboration with partners at University Jaume I (Spain) and East China University of Science and Technology (China) Hai contributed to the development of world-record efficiency quantum dot sensitized solar cells3. At present Hai is working on increasing the efficiency of electron transfer processes in photovoltaic building blocks; these works could pave the way towards solar cells with efficiencies exceeding the Shockley-Queisser limit (efficiencies beyond 30%).
1 Wang, H. et al. Tuning electron transfer rates through molecular bridges in quantum dot sensitized oxides. Nano Lett. 2013, 13, 5311−5315.
2 Wang, H. et al. Interplay between structure, stoichiometry, and electron transfer dynamics in SILAR-based quantum dot-sensitized oxide. Nano Lett. 2014, 14, 5780−5786.
3 Zhao, K. et al. Boosting Power Conversion Efficiencies of Quantum-Dot-Sensitized Solar Cells Beyond 8% by Recombination Control. J. Am. Chem. Soc. 2015, 137, 5602–5609.
New high-level functions for MAINZ PI Prof. Dr. Martin Aeschlimann
At the spring meeting of the German Physical Society (DPG), Prof. Dr. Martin Aeschlimann (MAINZ PI at TU Kaiserslautern) has been elected as speaker of the Society’s Condensed Matter Section (SKM). This section is the largest of the three sections of the DPG which in turn is the world's largest physical society. The section which Aeschlimann now heads for three years represents more than 18,000 members in 13 divisions. The scientific scope ranges from biological and chemical physics to surface physics and magnetism as well as physics of low temperatures. The SKM speaker is the scientific director of the spring meeting, which brings together far more than 6,000 participants every year. Next to the corresponding meeting of the American Physical Society (APS) it is the largest physics conference in the world.
Also at the DPG spring meeting Prof. Dr. Burkard Hillebrands (MAINZ PI at TU Kaiserslautern) was elected as speaker of the Magnetism Work Group. This work group is a joint committee of the DPG (Division on Magnetism), the German Society of Material Science (DGM), the VDE Scientific Association of Electrical Engineering, Electronic Information Technology Association, Energy-Technology Society (ETG in the VDE) and the German Association of Iron and Steel Research (VDEh). The Magnetism Work Group promotes scientific research and technical applications of magnetism in Germany, as well as in the European and global context. Lectures and discussion meetings are organized, and with the ThyssenKrupp Electrical Steel Dissertation Prize the promotion of young researchers is targeted.
2 MAINZ members admitted to the Gutenberg Academy
SPICE officially opened
MAINZ has been highlighted together with SpinNet in an article on Deutschland.de
(Picture © Jonas Ratermann - University of Mainz)
Full article ...
The state-funded project “Spintronic technology platform in Rheinland-Pfalz” (STeP) has been completed successfully
Physicists observe motion of tiny magnetic whirls - Skyrmions are candidates for future data storage and information processing
Small magnetic whirls may revolutionize future data storage and information processing if they can be moved rapidly and reliably in small structures. A team of scientists of Johannes Gutenberg University Mainz (JGU) and TU Berlin, together with colleagues from the Netherlands and Switzerland, has now been able to investigate the dynamics of these whirls experimentally. The skyrmions, as these tiny whirls are called after the British nuclear physicist Tony Skyrme, follow a complex trajectory and even continue to move after the external excitation is switched off. This effect will be especially important when one wants to move a skyrmion to a selected position as necessary in a future memory device. This research was published in the journal Nature Physics with a student of the Graduate School of Excellence Materials Science in Mainz (MAINZ) as the first author.
Skyrmions are small whirls in the magnetization of magnetic materials. In the case of the present work, the skyrmions have a diameter of less than 100 nanometers. This corresponds roughly to a thousandth of a hair width. To prepare these skyrmions, scientists at Mainz University prepared small magnetic discs. "When we apply a specific external magnetic field, the magnetization in these discs creates whirls," said Dr. Benjamin Krüger working in the group of Professor Mathias Kläui at the Institute of Physics at JGU. These skyrmions were then excited by a magnetic field pulse to trace their motion.
The scientists were now able to experimentally investigate the dynamics of these structures on short time scales for the first time. For these investigations, a holographic measurement setup using short and highly energetic X-ray pulses was used. This technique, which was developed at TU Berlin, can take images with a temporal separation of less than a nanosecond. The position of the whirl can be determined from these images to be compared with theoretical calculations.
"The measurements show that the skyrmions move on a very complex trajectory, a so- called hypo-cycloid," says Krüger. The fact that the skyrmions move on such a curved trajectory means that they must possess some inertia. This is comparable to a car that continues to move, even though the gas pedal is no longer pressed. The inertia of the skyrmion stems from the fact that the whirl can deform. In this way it is able to store energy; after the excitation has stopped, this energy leads to a continuation of the motion.
"This effect has not been taken into account up to now, but it is important for the development of small magnetic memories," explained Professor Mathias Kläui. "This effect has to be taken into account to enable the distinct positioning of the skyrmion in the memory." Skyrmions may be important for the future of magnetic data storage and information processing. These whirls can be moved rapidly and reliably along nanowires or other structures in future memories. Such a memory would retain its information even when the power is switched off. In addition, it would not need to contain any moving parts, such as a read and write head in a hard disk drive.
A comparison with computer simulations at Mainz University showed that the type of motion depends a little on the shape of the disk in which the whirl is formed. In addition, there is only a small dependence on defects in the material. There is, however, a substantial dependence on the shape of the whirl, its so-called topology. This implies that the present findings can be extended to all skyrmions with the same topology.
"I am happy about the good collaboration with our colleagues and about the fact that the experimental measurements, as well as the theory, were done by members of the JGU Institute of Physics and the MAINZ Graduate School of Excellence together," Kläui added. Funding of the Graduate School Materials Science in Mainz was approved in the Excellence Initiative of the German federal and state governments in 2007 and was prolonged by an additional five years in the second round of the initiative in June 2012. MAINZ combines work groups from Johannes Gutenberg University Mainz (JGU), the University of Kaiserslautern, and the Max Planck Institute for Polymer Research in Mainz. One of its research focuses is spintronics, a field in which collaborations with international partners play an important role. ...
2 MAINZ members selected for ERC Awards 2014!
MAINZ lecturer Martin Weides has been selected for an ERC Consolidator Grant with a project on interfacing spin waves with superconducting quantum circuits. MAINZ director Mathias Kläui has been selected for a Proof of Concept Grant on magnetic sensing.
Dr. Michael Fuchs new MAINZ General Manager
On January 2nd Dr. Michael Fuchs took over the position as MAINZ general manager. Prior to this, he worked for the DFG head office. He follows Dr. Mark Bajohrs who has taken over position as head of dean's office in the JGU’s faculty of biology. ...
Mathias Kläui has been appointed Fellow of the Institute of Physics (IOP) due to his achievements in the field of physics and his contributions in nanomagnetism and spin dynamics
MAINZ PhD Christoph Kreitner (group of Prof. Heinze) publishes a cover article in the European Journal of Inorganic Chemistry 2014
Interregional Research Award 2014 for the group of Prof. Katja Heinze (Institute of Inorganic Chemistry and Analytical Chemistry)
Together with their cooperation partner Centre de Recherche Public – Gabriel Lippmann (Luxembourg) the group of Prof. Katja Heinze is awarded the Interregional Research Award 2014 (first prize, 35.000 €). In this multinational cooperation project (SURFAMINE) – funded by the Fonds National de la Recherche – novel intelligent foils for food packaging have been developed.
Within the SURFAMINE project the teams have designed, synthesized and employed novel pigments for incorporation into a plasma-deposited layer suitable for food packaging. These intelligent foils detect spoiled food via a colorimetric signal of the embedded pigment upon its interaction with volatile amines formed by bacterial decomposition of amino acids. ...
Topological states of matter can be grown like crystals
Topological order, emerging as a collective behavior of a physical system, is an intriguing concept which attracted growing interest in many fields of physics during the last years. It allows to classify phases of matter that are not characterized by symmetries alone. Beyond the fundamental interest in such phases, they have intriguing applications in quantum computation and may be of significant practical relevance.
Recently it has been argued that ultra cold quantum gases as well as photonic systems can be promising platforms to investigate topological order in a way that is inaccessible in the solid-state. While the required Hamiltonians are essentially available in the laboratory today, a major challenge is to find a reliable scheme for the preparation of the corresponding ground states especially in interacting systems. In particular, most of previous works suggested adiabatic approaches that rely on finite-size energy gaps, and therefore, are doomed to fail for larger system sizes. A team of researchers from the group of M. Fleischhauer at the University of Kaiserslautern lead by MAINZ student Fabian Grusdt has now developed a new approach for growing quantum states with topological order, which overcomes these problems. In an international collaboration with M. Hafezi from the Joint Quantum Institute / NIST in the Washington D.C. area they proposed and analyzed a scheme that works much like conventional crystal growth. They show that starting from a small number of particles, half-filling Laughlin states of bosons can be grown by adding particles along with magnetic flux quanta one-by-one. This is achieved by combining a simple coherent pump with an interaction-blockade and a topologically protected, so called Thouless pump. The scheme can be applied to experiments in circuit quantum electrodynamics with current technology, and paves the way towards preparing more complicated topologically ordered states with exotic properties such as non-Abelian braiding statistics.
The work has been published recently in the prestigious journal Physical Review Letters:
F. Grusdt, F. Letscher, M. Hafezi, M. Fleischhauer, Physical Review Letters 113, 155301 (2014). ...
MAINZ Visiting Professorship 2014 awarded to Prof. Stephan Link (on the right) and Prof. Andrei Slavin (on the left)!
MAINZ Award 2013 awarded to Dr. Leonie Mück and Dr. Christoph Schüll!
MAINZ Director Mathias Kläui interviewed for "Welt der Physik" podcast
MAINZ Associated Member Román Orús was awarded the Early Career Prize of the European Physical Society
JACS Publication on One-Pot Synthesis and AFM Imaging of a Triangular Aramide Macrocycle with participation of the former MAINZ Member Christoph Hauke
Macrocyclizations in exceptionally good yields were observed during the self-condensation of N-benzylated phenyl p-aminobenzoates in the presence of LiHMDS to yield three-membered cyclic aramides that adopt a triangular shape. An ortho-alkyloxy side chain on the N-benzyl protecting group is necessary for the macrocyclization to occur. Linear polymers are formed exclusively in the absence of this Li-chelating group. A model that explains the lack of formation of other cyclic congeners and the demand for an N-(o-alkoxybenzyl) protecting group is provided on the basis of DFT calculations. High-resolution AFM imaging of the prepared molecular triangles on a calcite(10.4) surface shows individual molecules arranged in groups of four due to strong surface templating effects and hydrogen bonding between the molecular triangles.
Journal of the American Chemical Society 136(37), 12832-12835 (2014)
C. Storz, M. Badoux, C.M. Hauke, T. Šolomek, A. Kühnle, T. Bally, A.F.M. Kilbinger
doi: 10.1021/ja506646s ...
Mathias Kläui elected as director of the Gutenberg Nachwuchskolleg
As director of the Graduate School of Excellence Materials Science in Mainz, Mathias Kläui has broad experience in supporting PhD students. This know-how in addition to his previous experience in support organizations for postdoctoral fellows and academies of sciences for young scientists will be used to develop support measures tailored to young scientists at Johannes Gutenberg University Mainz. For more information (in German) please click on the link below. ...
Gutenberg Nachwuchskolleg der Johannes Gutenberg-Universität Mainz nimmt Arbeit auf
JGU investiert jährlich 1.000.000 Euro in die nachhaltige Verbesserung der Arbeits- und Betreuungsbedingungen des wissenschaftlichen Nachwuchses
Mit der Einrichtung des Gutenberg Nachwuchskollegs (GNK) eröffnet die Johannes Guten-berg-Universität Mainz einen innovativen Weg zur Förderung des wissenschaftlichen Nach-wuchses. „Als Expertengremium im Rahmen der Exzellenzinitiative des Bundes und der Länder konzipiert, dient das Kolleg der Strukturierung und Kommunikation bestehender sowie der Entwicklung neuer Förderformate“, erklärt der Präsident der Johannes Gutenberg-Universität Mainz, Univ.-Prof. Dr. Georg Krausch, anlässlich der konstituierenden Sitzung. „Das GNK zielt dabei insbesondere auf die nachhaltige Verbesserung der Arbeits- und Betreuungsbedingungen des wissenschaftlichen Nachwuchses und der Bereitstellung individueller Unterstützungsangebote in den Karrierephasen zwischen Promotion und Festanstellung als Universitätsprofessorin bzw. -professor.“ ...
MAINZ Faculty Member Michael Fleischhauer appointed to the Academy of Sciences and Literature in Mainz
The Academy of Sciences and Literature in Mainz has appointed Prof. Dr. Michael Fleischhauer from the Department of Physics at the University of Kaiserslautern as a new full member.
Professor Fleischhauer studied Physics at the Friedrich-Schiller Universität Jena and also obtained his PhD for research about non-classical properties of light there in 1991. After several research stays in the U.S., in New Mexico, in Texas and at Harvard University, he achieved his habilitation at the Ludwig-Maximilians-Universität München in 2000. In the same year he was appointed by the University of Kaiserslautern as Professor for Theoretical Physics. In his research Michael Fleischhauer developed, among others, an important procedure for the storage of quantum states. The method known as “Stopped Light” is a crucial feature for a photon-based quantum communication system. The internationally renowned theoretical Physicist is MAINZ Faculty and member of the State Research Center Optics and Material Sciences (OPTIMAS) of the University of Kaiserslautern. Next to research and teaching at the University of Kaiserslautern, the 51 year old physicist is also member of the editorial board of the renowned scientific journal Physical Review Letters. From 2008 to 2010 he headed the section “Quantum Optics and Photonics” of the Deutsche Physikalische Gesellschaft (German Physical Society, DPG), since 2012 he is member of the steering board of this world’s largest physical society. ...
Active particles may enhance phase separation
MAINZ at the Fourth International Conference for Young Scientists - Natural Resources in a Finite World
Mathias Kläui was invited to the meeting to discuss the impact of limited Natural Resources and the transformation to a sustainable world in particular with the respect to Materials Science and Engineering. The meeting gathers young scientists from around the world to discuss societal challenges and is organized by the Global Young Academy and supported by the International Council for Science together with further partners.
Picture: M. Kläui with B. Wrobel and H. Alper (right), Materials Chemist, Chair of Science, Technology and Innovation Council and previous Co-Chair of the InterAcademy Panel the Association of all Academies of Sciences....
MAINZ Faculty members Jairo Sinova and Stuart Parkin receive Humboldt Professorships!
The Humboldt Foundation has granted two Humboldt Professorships to MAINZ Faculty members Sinova and Parkin. Sinova will use the award money to create a new center called SPICE at JGU. Congratulations to both faculty members!...
MAINZ PIs Waldvogel and Tremel acquire third-party funding through DFG-funded SPP!
The senate of the DFG has selected the SPP “Tailored Disorder” as one of 16 new priority programs. MAINZ PIs Waldvogel and Tremel will receive funding through the SPP. MAINZ congratulates its PIs on their success!...
Controlling the direction of photochemistry
MAINZ PhD student Robert Lindner, working in the group of Angelika Kühnle, reports on a novel strategy to steer on-surface reactions. Taking advantage of the lattice mismatch, well-oriented, covalently linked C60 domains are formed on an insulator....
MAINZ External member Stuart Parkin picks up Millennium Prize 2014!
Stuart Parkin has been selected as the winner of the Millennium Prize 2014. Parkin has been an external member of MAINZ since 2010, is a fellow of the Gutenberg Research College and received the Gutenberg Research Award 2008 at JGU....
New holographic process uses image-stabilized X-ray camera
The group of Prof. M. Kläui (JGU), including MAINZ PhD student Felix Büttner, developed in collaboration with Prof. S. Eisebitt (TU Berlin) a new X-ray holography method that will enable snap-shots of dynamic processes at highest spatial resolution....
MAINZ Students join the JGU Gutenberg Academy
Christoph Kreitner (Heinze group), Stephan Köhler (Schmid group) and Daniel Rost (Binder group) were selected as new junior members of the Gutenberg Academy. The academy gives them the chance to participate in interdisciplinary exchange and to interact with outstanding researchers....
MAINZ scholarship holders and alumni of the German National Academic Foundation meet mayor of the city of Mainz to discuss support for disadvantaged pupils
The projects "Chancengleichheit" and "Teach First Deutschland" support disadvantaged pupils by providing coaching and tutoring. Both activities were presented to Michael Ebling, Lord Mayor of Mainz, and Prof. Dr. Mathias Kläui, Director of MAINZ....
MAINZ Alumni have met for the first time!
The first Alumni meeting of MAINZ has attracted fomer PhD students from all over Germany to come to Sörgenloch. Future meetings will take place annually on the last weekend in October....
Humboldt Professorship awarded to Jairo Sinova for MAINZ professorship in theoretical physics at JGU!
On initiative of MAINZ a new professorship in theoretical physics will be established in electronic and magnetic properties of condensed matter. Jairo Sinova has now received a Humboldt Professorship worth 3.5 Mio € associated with this position....
MAINZ Alumni awarded the MAINZ Award for their outstanding PhD theses within the Graduate School!
MAINZ Visiting Professorship awarded to Prof. Zabel!
Report on MAINZ Student Seminar 2013 online!
MAINZ student wins Poster Prize at IUPAC conference in Darmstadt!
MAINZ PI and student publish paper on Domain walls as new information storage medium in Nature!
MAINZ Visiting Professorship 2013 awarded to experimentalist Prof. Hartmut Zabel and theorist Prof. David Landau!
MAINZ Student Seminar 2014 takes place in Prague!
Registration for MAINZ Technical Trainings opens!
MAINZ Alumni Dr. Matthias Barz wins Emil and Paul Müller-Memorial-Foundation Award of JGU!
Group of MAINZ PI Carsten Sönnichsen presents novel multiplexed sensor!
MAINZ PhD student Fabian Grusdt at Harvard University
MAINZ PhD student Fabian Grusdt from Kasierslautern is currently on a one-year stay at the Physics Department of Harvard University. Being a PhD student of Professor Michael Fleischhauer (TU KL), Fabian currently is doing research with the group of Professor Eugene Demler who was one of the first recipients of the Gutenberg Lecture Award of the Graduate School MAINZ. He is working at Harvard on the theory of the preparation as well as the detection of topological quantum states in quantum optical systems. In recent years topological states of matter have triggered an increasing amount of interest due to their implications for error tolerant quantum information protocols, which is related to their exotic elementary excitations in many body quantum systems. In the group of Professor Demler quantum optical model systems, like e.g. cold quantum gases, are being investigated with special emphasis on their potential for the realization and investigation of exotic topological quantum phases....
First MAINZ Alumni Meeting to take place in autumn 2013!
JGU Gutenberg Research College Fellow Stuart Parkin (IBM Research Almaden) to receive honorary doctorate from MAINZ partner!
Thematic Network "SpinNet" with international partners of MAINZ kicks off!
The BMBF/DAAD-funded network will allow MAINZ PhD students to visit partners at IBM Research, Stanford University and Tohoku University. Additionally, partnerns will come to MAINZ for research and teaching. Joint summer workshops will also be organised....
Mentoring Program of MAINZ gets its name and logo
The mentoring program of MAINZ, mentMAINZ, is managed by Edeltraud Eller and starts with 13 mentees in year 2013 who applied to the program. New applications will be possible later this year for 2014....
MAINZ PI Jun.-Prof. Dr. Thomas Kühne publishes "Electronic signature of the instantaneous asymmetry in the first coordination shell of liquid water" in Nature Communications!
Mainz scientists confirm original tetrahedral model of the molecular structure of water
Researchers at Johannes Gutenberg University Mainz (JGU) have confirmed the original model of the molecular structure of water and have thus made it possible to resolve a long-standing scientific controversy about the structure of liquid water. "Our findings have important implications as they help reconcile the symmetric and asymmetric views on the structure of water," write the scientists in an article published in Nature Communications. The results may also be relevant to research into molecular and biological systems in aqueous solutions and provide insight into protein folding, for example. The work of Thomas Kühne's group was undertaken within an interdisciplinary joint project and was funded by the Research Unit Center for Computational Sciences at Johannes Gutenberg University Mainz....
MAINZ PhD student Felix Büttner wins Best Poster Award at the 12th joint Magnetism and Magnetic Materials - Intermag Conference
Recent results of the first direct dynamic imaging of single Magnetic Skyrmion Bubble domains were presented by Felix Büttner in his poster "Time-resolved Imaging of the Gyrotropic Motion of Magnetic Bubbles" at the annual 2013 Joint MMM - Intermag conference, the largest magnetism meeting in the world. At this conference in Chicago, USA he received unanimous votes as the best poster amongst more than 100 poster contributions for the exciting demonstration of the gyrating motion of skyrmionic domain structures in confined geometries....
MAINZ successful in attracting BMBF/DAAD funding for "Thematic Network"!
Funding for the proposed network SpinNet for 4-year period will be provided by the Federal Ministery of Education and Research through the German Academic Exchange Service. Apart from Johannes Gutenberg University, SpinNet includes partners from Stanford University, Tohoku University and IBM Research Almaden....
New MAINZ Videos online at our youtube Channel!
Watch our videos on bio-related materials, model systems and correlated matter and spintornics. All of them are available at our youtube channel....
Nomination for publication of the PhD thesis of MAINZ alumni Sebastian Will at Springer Verlag successful!
Springer Verlag has accepted the nomination of the PhD thesis of MAINZ alumni Sebastian Will by the MAINZ and the University of Munich as an outstanding contribution!...
External Member of MAINZ Stuart Parkin recognized for great service to interdisciplinary materials research
Experimental physicist Stuart Parkin of the IBM Almaden Research Center in San Jose, California and external member of MAINZ and the Gutenberg Research College received the von Hippel Award 2012....
An international research team including MAINZ student Felix Büttner found at FLASH a surprising effect!
This effect could be the key to further miniaturization and performance increase of magnetic data storage devices. The results have been published in the current issue of "Nature Communications"...
MAINZ Award for Christina Birkel and Christian Ohm
Christina Birkel received the award for her work on new methods of synthesizing nanoparticles from antimony compounds. Christian Ohm was recognized for his dissertation in the field of organic chemistry....
Gutenberg Lecture Award 2012 presented to Wolfgang Wernsdorfer from Institut Néel, CNRS (Grenoble)
Wernsdorfer received the award for his work on single molecular magnets, the magnetism of nanoparticles and for the development of the nano-SQUID....
MAINZ is successful in attracting funding for a second period in the Excellence Initiative
MAINZ student receives the Hugh Stott Taylor Award at Princeton University for the second time
Gold nanoantennas detect proteins - New method of monitoring protein molecules using gold nanoparticles
Scientists at Johannes Gutenberg University Mainz (JGU) have developed a new method of observing individual proteins. Detailed knowledge of the dynamics of proteins is necessary in order to understand the related biological processes that occur on the molecular level. The method developed by the group of Mainz chemists led by Carsten Sönnichsen is based on the use of gold nanoparticles. These serve as glistening nanoantennas that, when they detect individual unlabeled proteins, slightly change their frequency or, in other words, their color. These tiny color changes can be observed using the technique developed in Mainz....
JUnQ wins Special Award at "Deutscher Ideenpreis"
Tthe Journal of Unsolved Questions (JUnQ) is honoured at "Deutscher Ideenpreis" as a platform generating learning through publishing failure. The Special Award is given to JUnQ by a jury consisting of representatives from science, industry and politics....
Latest Advanced Functional Materials cover by MAINZ PhD student
Michael Schwall has suceeded in his bid for the latest cover of Advanced Functional Materials. The cover shows phase separation of a Heusler compound resulting in flower-like structures on the microscale. Schwall is persuing a PhD in the Felser group....
MAINZ and Princeton University meet for second workshop
PhD students of MAINZ and Princeton University meet at JGU Mainz for second workshop for scientific exchange and to foster further collaboration between both institutions. Leslie Schoop, a MAINz PhD Student from Claudia Felsers group, is currently performing her thesis project in Bob Cavas lab at Princeton to receive a double degree from Mainz and Princeton University.
MAINZ students organized most visited symposium ‘Spintronics on the way to modern storage technology” at DPG 2012 meeting in Berlin
A joint initiative of a jDPG and the magnetism division of the DPG has established a new format this year. A the format allows PhD students to organise a symposium at the DPG meeting for other students. This years symposium organised by several MAINZ students was a great success and being one of the most attended sessions during the 76th DPG Spring meeting in Berlin between March 25-30, 2012. The talks of world-known experts in the field of magnetism attracted a high proportion of both young scientists and senior researchers. The program was specifically tailored in a way that invited talks were stitched with contributed ones; so that the topic was covered from basics to modern applications.
The organising MAINZ PhD student team sincerely thanks Prof. M. Fiebig (ETH Zürich), Prof. H.-J. Elmers (JGU Mainz) and S. Köhler (JGU Mainz) for the organizational support and the Graduate School MAINZ for the financial support.
MAINZ PhD student wins Best Poster Award at the Intermag 2012
Felix Büttner was honoured for his outstanding poster "New soft high anisotropy materials for magnetization dynamics of solitonic spin structures" at the 2012 International Magnetics Conference (Intermag) in Vancouver, Canada. Mr. Büttner is currently carrying out a PhD on magnetic soliton dynamics in the group of Mathias Kläui.
MAINZ PhD student receives "Vodafone Förderpreis 2012"
The "Vodafone Förderpreis" worth 5000€ is awarded annually for diploma/master/PhD thesis for outstanding research in the field of mobile communications. Hubertus Braun was awarded "Vodafone Förderpreis" for his diploma thesis on the development and investigation of low loss dielectric glass-ceramic materials for the use as dielectrics in microwave electronics. He performed his diploma thesis under supervision of G. Jakob and in collaboration with SCHOTT (Martin Letz) as well as the Technical University of Darmstadt (Rolf Jakoby). Braun has joined MAINZ recently and is currently pursuing a PhD in the group of H.J. Elmers....
Micromagnetics Tutorial in MAINZ
Prof. U. Nowak and Dr. K. Lebecki from the University of Konstanz give a Tutorial for Micromagnetics for MAINZ students and interested PhD students from the Chemistry and Physics departments at JGU. In addition to a theoretical lecture, two hands-on session were given to allow students to carry out their own simulations quickly. Micromagnetics describes the dynamics of magnetization on the nanoscale using numerical simulations and bridges time and length scales from ab-initio calculations to macroscopic properties. Prof. Nowak and Prof. Kläui have a joined project where theoretical and experimental studies work hand in hand to investigate the influence of temperature on magnetization.
MAINZ PhD students Olga Meshcheriakova, Sandra Perkert, Dima Kutnyakhov and Christian Mix were successful in their bid to organize a Symposium for the DPG (German Physical Society) Spring Meeting
JUnQ finishes fourth in race for Hochschulperle 2011
For more informations about the contest, and all it's participants click here.
Third issue of the Journal of Unsolved Questions (JUnQ) published by the Graduate School MAINZ is now available
The 3rd issue of the Journal of Unsolved Questions (JUnQ) is now available online and in print. JUnQ was founded in 2010 by doctoral students of the Graduate School of Excellence "Materials Science in Mainz" (MAINZ) in cooperation with scientists from around Europe. Since then, the journal has generated a great deal of interest. Its goal is to provide a forum through which information can be made available on the kind of excellent but inconclusive scientific projects that established scientific journals tend to ignore....
JUnQ is up for election to become “University Pearl of the Year 2011"
MAINZ strengthens network in China!
Prof. Dr. Gerhard Wegner was awarded an honorary doctorate by the ETH Zurich
MAINZ PI gave inauguration lecture at JGU!
Robert J. Cava (Princeton University, Gutenberg Lecture Award 2011) receives Humboldt Fellowship for research visits at MAINZ/JGU and KIT!
Cava currently hosts one MAINZ PhD student in his laboratory at Princeton University who is aiming at a double degree from Princeton and from MAINZ/JGU. The Humboldt fellowship will allow Cava to spent time at MAINZ/JGU and at Karlsruhe Institute for Technolgy (KIT) to strenghten his ties with German researchers.
MAINZ PhD student receives Hugh Stott Taylor Prize of Princeton University for outstanding academic performance.
MAINZ PI receives ERC Advanced Grant worth 2,4 Mio Euro!
JGU president Krausch honors Kookheon Char (Gutenberg Research Award 2006) at Seoul National University.
MAINZ and JGU intensify existent partnerships with top-class universities in Asia. Krausch honored Kookheon Char by presenting him with the certificate of appointment as a Fellow of the GRC and MAINZ....
MAINZ PhD Student Leonie Mück wins Poster Prize at the Central European Symposium of Theoretical Chemistryin Poland
MAINZ members observe different states of electrons in Heusler materials!
Scientists of JGU and MAINZ were able to observe the behavior of electrons in Heusler materials through usage of a novel lightsource of Japanese partners. This way they want to discriminate between the materials properties....
JGU competes with other German universities in all three funding lines of the Excellence Initiative
Johannes Gutenberg University Mainz has submitted full proposals for a graduate school, three clusters of excellence, and its institutional strategy to promote top-level university research....
JGU proven to be internationnaly outstanding in the field of physics
The Academic Ranking of World Universities has listed the Institute of Physics of Mainz University as one of the 75 best worldwide....
Gutenberg Research Award 2011 of Graduate School MAINZ for Prof. Michael Graetzel
Prof Graetzel from EPFL (Lausanne, CH) contributed with major discoveries to the field of photovoltaics allowing the usage of solar energy in the future. Graetzel has published more than 800 papers and has received outstanding awards for his work....
MAINZ PI receives Nicholas Kurti Award 2011
Prof. Mathias Kläui awarded for research on nanomagnetism....
Support for optoelectronics in Mainz: Kookheon Char appointed as GRC fellow
Kookheon Char of the Korean elite institution Seoul National University has become a fellow of the GRC and will be mentoring doctoral students of the graduate school MAINZ....
Victor Zhu from UC Berkeley visits MAINZ for an Internship
MAINZ PhD student accepted at the Gutenberg Academy of Johannes Gutenberg University Mainz
The Gutenberg Academy is a program of JGU that supports young researchers and serves to foster interdisciplinary exchange. MAINZ PhD student Leonie Mück has just joint the academy and is now one of the two MAINZ members in the academy presently benefiting from the support offered. In total 22 PhD students of JGU are supported by the academy. ...
MAINZ PhD student Nicolas Vogel wins poster prize at Nanoplasmonics Symposium in Spain
Nicolas Vogel wins one of the two Nanoscale Poster Prizes on “Coupling of Plasmon Modes in Nano-Crescent Dimer Structures Fabricated by Colloidal Lithography”.
The International Workshop on Nanoplasmonics for Energy and the Environment was held from 8-10 June 2011 in Sanxenxo, Spain.
Open PhD positions in two collaborative projects with GRC-fellow Stuart Parkin from IBM Research Almaden (CA, USA)
The Graduate School MAINZ advertises two PhD positions with Stuart Parkin in collaborative supervision with PIs from MAINZ. Application closes on June 24, 2011 11:59 p.m. (GMT+1) via our online application interface. ...
Stuart Parkin receives GRC-Fellowship of the JGU to strenghten cooperation with MAINZ
Outstanding doctoral thesis of MAINZ students awarded the annual MAINZ Award
Robert J. Cava receives Gutenberg Lecture Award 2011 of Graduate School MAINZ
Top US researcher Robert J. Cava of Princeton University receives the Gutenberg Lecture Award for his research on superconductivity – a technology of the future
MAINZ PhD student project JUnQ awarded "Hochschulperle des Monats April" by Stifterverband der Wissenschaft!
"Hochschulperlen" are innovative projects which have been realised at a University. They are small but shiny. The Stifterverband awards this recognition monthly and pearls of one year have the chance to be named "pearl of the year". Keep your fingers crossed for our Journal of unsolved questions! Congratulations to the editors!
Rhineland-Palatinate strengthens universities participating in the Excellence Initiative!
Prime Minister Beck and Minister of Science assure JGU and TU Kaiserslautern financial assistance in case of successful results! ...
University of Mainz off to a flying start in the federal excellence competition!
Johannes Gutenberg University Mainz will hand-in prolongation proposal for the Graduate School Materials Science in Mainz (MAINZ), three proposals for excellence clusters (one related to our graduate school) and a future concept. Technical University Kaiserslautern will hand-in one proposal for an excellence cluster related to MAINZ. Proposals will be evaluated staring on September 1, 2011 by Deutsche Forschungsgemeinschaft and Wissenschaftsrat. Results are expected in summer 2012. ...
Interview of MAINZ PhD student Thomas Jagau on JUnQ by Deutschlandfunk now online (in German)!
Interview with Thomas Jagau on publication of scientific results and on the current practice not to publish negative results. The Journal of unsolved questions (JUnQ) publishes negative results and open questions. The idea of JUnQ was born in a think tank of the Graduate School MAINZ and is a project of our PhD students. ...
Doctoral students of "Materials Science in Mainz" publish first issue of Journal of Unsolved Questions
Our vision is establishing the publication of null-results as an important cornerstone for the advancement of knowledge and scientific understanding in all disciplines thus con- tributing to overcome biases and fraud in research. JUnQ is a new platform to gather ‘null’-result research. It is a medium to communicate projects, which just didn’t work, ambiguous data without exaggeration and unfinished investigations, which raise more questions than they answer. The idea of JunQ was born in a think tank of the Graduate School MAINZ and is a project of our PhD students. ...