Research

26.04.2022 Joint Publication about antiferromagnetic spintronics

A joint publication with Helen Gomonay about  magnetoelastic effects at the interface of antiferromagnetic-ferromagnetic bilayers has been published in Physical Review B.

They show that surface acoustic waves at the interface of both magnets can be used to find complex magnetic textures.They are able to connect the magnetoelastic resonance to spin spirals in both layers.The reulst add to the emergent research in using noncollinear magnetism in spintronics devices.

You can find the publication under PhysRevB.105.144432.

25.03.2022 Joint publication about antiferromagnetic spintronics

A joint publication with Helen Gomonay about  ultrafast manipuation of antiferromagnets  has been published in Communications Physics.

They show a theoretical mechanism to imprint spin chirality into collinear antiferromagnets with the use of laser pulses. These pulses then can lead to quasi-stable ciral states. The results provide a more detailed  insight on the interactions between light and chiral magnetism.

You can find the publication under nature.com/articles/s42005-022-00840-3.

10.02.2022 Publication about Unconventional Antiferromagnets

 

A publication from the team of antiferromagnetic spintronics about giant and tunneling magnetoresistance in unconventional collinear antiferromagnets has been published in Physical Review X.

They presentc archetype model mechanisms for the giant and tunneling magnetoresistance effects in multilayers of such materials. These mechanisms are linked to real materials through ab-initio calculations. Further they show how their models can allow for magnetic excitations by teh spin transfer torque.

You can find the publication under PhysRevB.12.011028.

07.02.2022 Joint publication about antiferromagnetic spintronics

A joint publication from the team of antiferromagnetic spintronics about domain walls driven by elastic defects has been published in Nature Communications.

They show that the domain structure in thin films of the antiferromagnet CuMnAs is dominated by elastic defects. These defects determine the location and orientation of 90° and 180° domain walls.The results show the impact of defects on the antiferromagnetic domain structure and provides a route to optimize the performance of devices.

You can find the publication under nature.com/articles/s41467-022-28311-x.

01.02.2022 Joint Publication in antiferromagnetic spintronics

A joint publication of the Kläui - Lab together with Olena Gomonay and Jairo Sinova about magnon transport in weak antiferromagnets has been published in the Journal of Magnetism and Magnetic Materials. 

In more detail, they studied the antiferromagnet hematite with the Dzyaloshinskii-Moriya interaction (DMI). The results show that the DMI gives a new reconfigurability in the long distance magnon transport within thin films. This introduces a hysteresis in the system as a consequense of a competiotion of the Zeeman field and the effective field of the DMI.

You can find the publication under j.jmmm.2021.168631.

28.01.2022 Publication by Ricardo Zarzuela and Jairo Sinova

A publication by Ricardo Zarzuela and Jairo Sinova about the spin-charge transport theory and spin-transfer physics in frustrated magnets has been published in Physical Review B.

They present a new theory based on the doped Hubbard model and the slave-boson formalism. The results of their work point towards possible new Hall physics thhat was previously unanticipated  in the studied frustrated materials.

You can find the publication under PhysRevB.105.024423.

12.01.2022 Joint publication with Jairo Sinova

A joint publication of the London Centre for Nanotechnology and the Catalan Institute of Nanoscience and Nanotechnology together with Jairo Sinova about Van der Waals layered systems has been published in Nature Reviews Physics.

They present fundamentals on van der Waals magnetism and spin–orbit coupling effects in 2D systems. It is discussed how the coexistance of both effects could establish new ways to engineer robust spin textures. The results will help in designing future non-volatile memory devices that utilize the unique properties of 2D materials.

You can find the publication under nature.com/articles/s42254-021-00403-5.

04.06.2020 New Science Advance publication on the prediction of the Crystal Hall effect.

Libor Smejkal has predicted a new type of phenomena in the family of spontaneous Hall effects connected to a new type of exchange splitting that depends on the momentum of the electron quasiparticle.

Abstract: Electrons, commonly moving along the applied electric field, acquire in certain magnets a dissipationless transverse velocity. This spontaneous Hall effect, found more than a century ago, has been understood in terms of the time-reversal symmetry breaking by the internal spin structure of a ferromagnetic, noncolinear antiferromagnetic, or skyrmionic form. Here, we identify previously overlooked robust Hall effect mechanism arising from collinear antiferromagnetism combined with nonmagnetic atoms at noncentrosymmetric positions. We predict a large magnitude of this crystal Hall effect in a room temperature collinear antiferromagnet RuO2 and catalog, based on symmetry rules, extensive families of material candidates. We show that the crystal Hall effect is accompanied by the possibility to control its sign by the crystal chirality. We illustrate that accounting for the full magnetization density distribution instead of the simplified spin structure sheds new light on symmetry breaking phenomena in magnets and opens an alternative avenue toward low-dissipation nanoelectronics.

https://advances.sciencemag.org/content/6/23/eaaz8809

01.06.2020 – CRC TRR288 Elastoqmat funded by the DFG

The DFG has funded the CRC TRR288 ELASTO-Q-MAT initiative. It involves the JGU (Sinova co-speaker), Goethe University Frankfurt (Roser Valenti as coordinator and speaker), the Karlsruhe Institute of Technology (Joerg Schmalian co-speaker), and the Max Plank Institutes in Mainz and Dresden. This initiative has the goal to understand, advance, and exploit new physical phenomena emerging from a particularly strong coupling between a material's elasticity and its electronic quantum phases. To this end, we will study the effects of elastic tuning and elastic response of various types of electronic order in representative classes of quantum materials that share a high sensitivity to intrinsic strain or externally applied stress fields

https://www.uni-mainz.de/presse/aktuell/11474_DEU_HTML.php

 

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19.12.2017 – Olena Gomonay receives DFG grant

We congratulate Olena (Helen) Gomonay on obtaining her first DFG research grant “SHARP: Spintronics witHAntiferRomagntes and Phonos”. Well done Helen!

The proposed research project will open and explore new ways to detect and manipulate antiferromagnets using phonons and magneto-elastic coupling effects.