GP-Spin Seminar
Tuesday, April

18

4:30 pm – 6:00 pm

Tutorial Part I: Spin-Orbitronics and Applications in low power Memory
Wednesday, April

19

10:00 am – 11:30 am

Antiferromagnetic Spintronics: Writing, Reading and Transporting
Information for next generation devices
Tuesday, April

20

4:30 pm – 6:00 pm

Tutorial Part II: Skyrmions and Applications in Unconventional Computing

PROF. DR.

MATHIAS KLÄUI
Instutute of Physics & Materials Science in Mainz, Johannes
Gutenberg Universiy
Venue: Seminar Room, 2nd floor, AIMR Main Building
Katahira Campus, Tohoku University
Katahira Campus North Gate

AIMR Main Building

Co-hosted by AIMR

Contact: GP-Spin Office
spin.all[at]tohoku.ac.jp022-795-3657 /3487

Tutorials on Spin-Orbitronics and Skyrmionics– novel science and applications in memory & unconventional computingfor GreenIT
Mathias Kläui1,2

12Institute of Physics, Johannes Gutenberg University Mainz, 55099 Mainz, Germany
Centre for Quantum Spintronics, Department of Physics, Norwegian University of Scienceand Technology, 7034 Trondheim, Norway.

Novel spintronic devices can play a role in the quest for GreenIT if they are stable and can transportand manipulate spin with low power. Devices have been proposed, where switching byenergy-efficient approaches is used to manipulate topological spin structures [1,2].
We combine ultimate stability of topological states due to chiral interactions [3,4] with ultra-efficient
manipulation using novel spin torques [3-5]. In particular orbital torques [6] increase the switchingefficiency by more than a factor 10 enabling low power memory devices.
We use skyrmion dynamics for non-conventional stochastic computing applications, where wedeveloped skyrmion reshuffler devices [7] based on skyrmion diffusion, which also reveals the originof skyrmion pinning [7]. Such diffusion can furthermore be used for Token-based Brownian
Computing and Reservoir Computing [8].

References[1] G. Finocchio et al., J. Phys. D: Appl. Phys., vol. 49, no. 42, 423001, 2016.
[2] K. Everschor-Sitte et al., J. Appl. Phys., vol. 124, no. 24, 240901, 2018.
[3] S. Woo et al., Nature Mater., vol. 15, no. 5, pp. 501–506, 2016.
[4] K. Litzius et al., Nature Phys., vol. 13, no. 2, pp. 170–175, 2017.
[5] K. Litzius et al., Nature Electron., vol. 3, no. 1, pp. 30–36, 2020.
[6] S. Ding et al. Phys. Rev. Lett. 125, 177201, 2020; Phys. Rev. Lett. 128, 067201, 2022.
[7] J. Zázvorka et al., Nature Nanotechnol., vol. 14, no. 7, pp. 658–661, 2019;
R. Gruber et al., Nature Commun. vol. 13, pp. 3144, 2022.
[8] K. Raab et al., Nature Commun. vol. 13, pp. 6982, 2022;
M. Brems et al., Appl. Phys. Lett. 119, 132405, 2021.

Antiferromagnetic Spintronics: Spintronics without magnetic fields
Mathias Kläui1,2,*Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
2
Centre for Quantum Spintronics, NTNU, 7034 Trondheim, Norway*IEEE Magnetics Society Distinguished Lecturer 2020/2021
Klaeui@uni-mainz.de1

While known for a long time, antiferromagnetically ordered systems have previously been considered, as“interesting but useless”. However, since antiferromagnets potentially promises faster operation, enhanced
stability and higher integration densities, they could potentially become a game changer for new spintronic
devices. Here I will show how antiferromagnets can be used as active spintronics devices by demonstrating
the key operations of “reading” [1], “writing” [2], and “transporting information” [3] in antiferromagnets.
Beyond typical bulk and thin film systems, recently also antiferromagnetic van der Waals materials havebeen discovered [4], which bode particularly well for manipulation by efficient interface effects.
[1] S. Bodnar et al., Nature Commun. 9, 348 (2018); L. Baldrati et al., Phys. Rev. Lett. 125, 077201 (2020)[2] L. Baldrati et al., Phys. Rev. Lett. 123, 177201 (2019); H. Meer et al., Nano Lett. 21, 114 (2020); S. P.
Bommanaboyena et al., Nature Commun. 12, 6539 (2021);[3] R. Lebrun et al., Nature 561, 222 (2018). R. Lebrun et al., Nature Commun. 11, 6332 (2020). S. Das et al., NatureCommun. 13, 6140 (2022).
[4] R. Wu et al., Phys. Rev. Appl. 17, 064038 (2022).

Mathias Kläui is professor of physics at Johannes Gutenberg-University Mainz andadjunct professor at the Norwegian University of Science and Technology.
He received his PhD at the University of Cambridge, after which he joined the IBMResearch Labs in Zürich. He was a junior group leader at the University of Konstanzand then became associate professor in a joint appointment between the EPFL andthe PSI in Switzerland before moving to Mainz. His research focuses on
nanomagnetism and spin dynamics on the nanoscale in new materials. His researchcovers from blue sky fundamental science to applied projects with major industrial
partners. He has published more than 300 articles and given more than 200 invited
talks. He is a Fellow of the IEEE, IOP and APS and has been awarded a number ofprizes and scholarships. He was also a visiting professor at Tohoku University in2016 and he has been one of the 2020/2021 IEEE Magnetics Society Distinguished
Lecturers.
Contact details and more information at www.klaeui-lab.de