Former News

LSND-News Feed (2010 - 2012)
December 2012: Joint research on Heusler compounds with Prof. Miyawaki from Nagoya

After previous visits to Mainz and a visit of Prof. Kläui to Nagoya, a long term partnership with the group of Prof. Asano and Prof. Miyawaki from Nagoya University has been established. Prof. Miyawaki will stay with us all of decembre to carry out high resolution imaging as well as magnetotransport measurements on Heusler heterostructures including all-Heusler spin valves and exchange bias systems.

Octobre 2012: Publication Highlight in Nature Communications

In collaboration with an international team of researchers we have found at the free electron laser FLASH a surprising effect that leads in ferromagnetic materials to a spatially varying magnetization manipulation on an ultrafast timescale. The results have been published in the current issue of „Nature Communications” (DOI 10.1038/ncomms2108).

It is known that magnetization can be manipulated by short light pulses but so far the spatially - resolved magnetization change could not be determined due to the limited spatial resolution of conventional optical techniques. Since most of the ferromagnetic materials consist of multiple domains with different magnetization directions, the local change of the magnetization in these domains and at the interfaces between the domains (domain walls) is of particular interest. At the FLASH free electron laser at the DESY Research Center in Hamburg, results were obtained that are in agreement with a recently theoretically predicted mechanism: due to the laser pulses, highly excited electrons are generated that move quickly through the material. They thus move from one domain into a neighboring domain with a different magnetization direction. Since the electrons carry part of the magnetization, they manipulate the magnetization in the domains as they move across a domain wall. This means, domain walls can change their profile on the fs time scale.

The experiments were carried out in a collaboration with researchers from the TU Berlin, the University of Hamburg, Paris and six further research institutes at the free electron laser FLASH at DESY in Hamburg.

August 2012: Yenny Hernandez appointed assistant professor

Yenny Hernandez was appointed assistant professor (tenure track) at Universidad de los Andes - Bogota from August 1st. She will leave our group but continue to work on carbon structures and collaborate with our group in particular on turbostratic graphitic microstructures.Congratulations and good luck to her.

July 2012: Prof. Miyawaki from Nagoya visiting

Prof. Tetsuya Miyawaki from Nagoya University is visiting the group as a guest Professor as part of a collaboration on iron based Heusler compounds. High resolution magnetic imaging is being used to study the advanced thin film structures prepared in Nagoya and ascertain the magnetic properties. As part of a long term joint project, the growth expertise in Nagoya is combined with the magnetic imaging know-how at Mainz.

July 2012: Wolfgang Wernsdorfer receives Gutenberg Lecture Award

Wolfgang Wernsdorfer from the CNRS Institut Néel in Grenoble received the Gutenberg Lecture Award, which is annually awarded by the graduate school of excellence Materials Science in Mainz (MAINZ) to leading researchers in Materials Science. At the award ceremony, Dr. Wernsdorfer received the certificate from MAINZ director Mathias Kläui. Dr. Wernsdorfer has longstanding ties with the group of Prof. Kläui with a number of joint publications and the collaboration will be intensified in particular in the field or spin transport in graphene and organic compounds.


June 2012: Publication Highlight - Paper selected for Virtual Journal of Nanoscale Science & Technology

The recent publication on the interaction between spin waves and domain walls (J.-S. Kim et al., Phys. Rev. B 85, 174428 (2012)) was selected as a highlight vor the Virtual Journal of Nanoscale Science & Technology. The interaction is strongly dependent on the frequency of the spin waves and motion in the direction of the spin wave propagation as well as against this direction is observed and explained based on different mechanisms that dominate for resonant and non-resonant interactions.

June 2012: Physics in Mainz leading in third party funding

The physics department of the University of Mainz is one of the most successful in obtaining third party funding from the German Science Foundation.

Mainz has the 6th largest total DFG project funding and is number 3 for funding when excluding excellence initiative projects.

More information here and here.

June 2012: Success in the Excellence Initiative - Graduate School and Cluster granted!

The German Science Foundation announced that the application for the Graduate School of Excellence "Materials Science in Mainz" was successful with an increased budget. With this prolongation under the new director Mathias Kläui, the successful research and training program in Materials Science will be continued and further developed including strengthening new research areas.

The graduate school is a collaborative project between the Johannes Gutenberg-University of Mainz, the Kaiserslautern University of Technology and the Max Planck Institute for Polymer Research.

More details about the Graduate School can be found at

Furthermore the Cluster of Excellence Precision Physics, Fundamental Interactions and Structure of Matter was also granted making the Physics department at Mainz one of the most successful in Germany.

May 2012: Hubertus Braun receives Vodafone Prize

Hubertus Braun has been awarded the Vodafone Support Prize 2012 of the Vodafone foundation for his master thesis on
,Glass ceramics with paraelectric phases for mobile applications in the GHz range’, which was carried out under the supervision of Gerhard Jakob.
The prize ceremony took place in the Albertinum in Dresden.
More information can be found here.

May 2012: Felix Büttner wins Best Poster Award at the Intermag 2012 Conference

The work of Felix Büttner on Magnetic Soliton Dynamics was presented as a poster "New soft high anisotropy materials for magnetization dynamics of solitonic spin structures" at the 2012 International Magnetics Conference (Intermag) in Vancouver, Canada. His contribution was selected from more than 100 posters for the high scientific quality as well as the presentation.Information on the research can be found here.
Felix Büttner is a PhD student within the Graduate School of Excellence Materials Science in Mainz (MAINZ).

intermag award

April 2012: Prof. Miyawaki as Guest Professor

Prof. Tetsuya Miyawaki from Nagoya University is staying in the group as a guest Professor. Prof. Miyawaki is a specialist on iron based Heusler compounds. Combining the know-how on the preparation of high quality thin films with the magnetotransport expertise in the group will be used to study the prospect of using these compounds in spintronics devices.

March 2012: Christian Mix co-organizer of the first young DPG symposium for the DPG (German Physical Society) Spring Meeting

Christian Mix has co-organized a symposium on Spintronics on the way to modern storage technology. The idea to solicit proposals for a symposium from PhD students for PhD students is a joint initiative of the magnetism division and the young DPG. The symposium is a special session of the DPG Spring meeting in Berlin, March 25-30, 2012.

February 2012: Visit of Dr. T. Moore funded by Humboldt Scholarship

Dr. Thomas Moore is a lecturer at the University of Leeds who is currently visiting the group funded by the Alexander von Humboldt Foundation. Dr. Moore works on spin torque and spin orbit effects in high anisotropy materials without inversion asymmetry leading to strong Rashba fields. Dr. Moore has a longstanding tradition of working with the group with two joint publications in Physical Review Letters in the last two years.

January 2012: Simone Finizio joins as a MAINZ scholar

Simone Finizio joined us as a PhD student after being successful in the last round of the competition for the Graduate School of Excellence Materials Science in Mainz (MAINZ). Simone recently passed his Master at the Politecnico di Milano with the top grade and joins us to work on spin and charge dynamics in oxidic nanostructures.

December 2011: Sebastian Schweitzer obtains distinction for his Diploma

Congratulations to Sebastian Schweitzer for his outstanding work on Charge and Spin Transport in Turbostratic Graphene. This collaborative work with the MPI for Polymer Science in Mainz (Group of Prof. Müllen) yielded high mobilities in mechanically robust Graphene superstructures. With the distinction for the thesis Sebastian also came top in his class and will be awarded a distinction for his overall performance.

The work is performed as part of a project in the DFG funded priority program "Graphene".

December 2011: Andreas Kehlberger successful in MAINZ Graduate School of Excellence Application

Congratulations to Andreas Kehlberger who was selected to be a member of the Graduate School of Excellence Materials Science in Mainz (MAINZ). The jury commended his innovative approach to generating spin currents using the recently discovered spin Seebeck effect.

December 2011: Tobias Eichhorn receives Ph.D. for his research on magnetic shape memory materials

Congratulation to Tobias Eichhorn who defended his Ph.D. thesis successfully.His research focused on the microstructure of epitaxial thin films of the ferromagnetic shape memory alloy Ni2MnGa. This material changes its shape under influence of a magnetic field. The work is carried out as a part of a project of Prof. Jakob within the priority programme 1239 of the German Science Foundation:

Change of microstructure and shape of solid materials by external magnetic fields

17. November 2011: Antrittsvorlesung Prof. Dr. M. Kläui

Spintronics beyond the conventional approach:

Nanoscale magnetic systems for low power electronics

Beginn: 16:00 Uhr c.t. , Auditorium maximum, Alte Mensa, Johann-Joachim-Becher-Weg 5

November 2011: Felix Büttner successful in excellence graduate school application

Congratulations to Felix Büttner who was selected as a member of the graduate school of excellence Materials Science in Mainz (MAINZ). The jury commended his work on ultrafast magnetization manipulation and the further development of the x-ray holography technique.

September 2011: Review Paper selected for Materials Science and Engineering Reports Cover

The recently published extensive review on "Current-induced domain wall motion in nanoscale ferromagentic elements" was selected for the cover page of the September Issue of Materials Science and Engineering Reports. The full publication can be found at: O. Boulle et al., Materials Science and Engineering Reports 72, 159 (2011).

August 2011: Shanghai Ranking

The Institute of Physics at Johannes Gutenberg University Mainz (JGU) in Germany has been listed in the Academic Ranking of World Universities (ARWU) among the top 75 research institutes of its kind worldwide. It has also been named as one of the six best institutes of physics in Germany.

More information can be found here.

July 2011: M. Kläui receives Nicholas Kurti Prize

At the Magentics and Optics Research International Symposium 2011 M. Kläui was awarded the 2011 Nicholas Kurti Prize for Research in the Physical Sciences. The Nicholas Kurti prize is annually awarded for outstanding work of a young scientist in the field of research at low temperatures or at high magnetic fields. More information can be found here or see the press release.

November 2010: Publication Highlight in Physical Review Letters and Physics

In Physical Review Letters 105, 187203 (2010), we published our recent work on Direct Determination of Large Spin-Torque Nonadiabaticity in Vortex Core Dynamics. The paper was selected as as an editor's choice as one of the most interesting papers in that issue. Highlight these exciting results further, the story was covered in a Viewpoint article in the journal Physics 3, 91 (2010).

The racetrack memory device was envisaged by Stuart Parkin at the Almaden IBM research center (US Patent 6 834 005 and Science 320, 190 (2008)). In this device, the information is stored as magnetic domains delineated by a domain wall. This principle is similar to magnetic tape (such as a video cassette) but in contrast to tape where the information is physically moved with the tape, in the racetrack the information is moved inside the tape by injecting spin polarized currents and the racetrack stays fixed with no mechanical motion. A layman's description (in german) can be found in Physik in unserer Zeit.

In our work, we have investigated the underlying physics that allows for the displacement of domains and domain walls. This so-called spin transfer torque leads to a motion of the domains and domain walls in the electron flow if a spin-polarized current is injected. The speed is governed by the non-adiabaticity parameter, which characterizes the spin polarized charge carrier transport across a spin texture such as a domain wall. By measuring the displacement of a vortex core in a magnetic disc, we find that for these vortex cores the non-adiabaticity parameter is larger than expected and from this one could deduce possible velocities for domain walls including vortices that are higher than those currently measured. We have found using an independent method that vortices in vortex walls exhibit the same high non-adiabaticity (Physical Review Letters 105, 56601 (2010)) as found for the vortices in discs in this work.

Since it is the speed of the domain walls that governs the access (read/write) times of the device, this would make the racetrack a formidable competitor as a non-volatile memory device.

October 2010: Matthias Eltschka receives Best Master Student of the year award

For his Master thesis on Thermally activated domain wall hopping biased by spin polarized currents and his excellent grades, M. Eltschka received the annually awarded Prize of the University of Konstanz Alumni Association. M. Eltschka is already the second student from the group to receive this prize that was handed over at the annual graduation ceremony on 15.10.2010 by Prof. Appell.