Funding period: 2021 – 2024

Project leader: Ulrich Nowak

Scientific staff: Moumita Kundu

Former members: Martin Evers, Severin Selzer, Markus Weißenhofer

This project focuses on spin fluctuations as caused by magnonic spin currents in different types of magnetic insulators and their heterostructures. Within the framework of spin model simulations, the properties of this spin noise and its interaction with magnetic textures, such as domain walls, will be investigated. Goals of the project are to establish a deeper understanding of the role of these nonequilibrium spin fluctuations for physical effects, which are related to magnonic spin transport, and to uncover in how far these fluc­tuations are exploitable for the characterization and functionality of magnonic devices.

List of publications

2024

• Two levels of topology in skyrmion lattice dynamics​​​​​​​
  D. Schick, M. Weißenhofer, L. Rózsa, J. Rothörl, P. Virnau, and U. Nowak
  Phys. Rev. Research 6, 013097 – published 25 January 2024

2023

• Defect-enhanced diffusion of magnetic skyrmions
  P. Rieger, M. Weißenhofer, and U. Nowak
  Phys. Rev. B 108, 144417 – published 17 October 2023
   
• Magnon squeezing in conical spin spirals
  D. Wuhrer, L. Rózsa, U. Nowak, and W. Belzig
  Phys. Rev. Research 5, 043124 – published 6 November 2023
  also related to project A03 and B06
   
• Enhanced thermally-activated skyrmion diffusion with tunable effective gyrotropic force
  T. Dohi, M. Weißenhofer, N. Kerber, F. Kammerbauer, Y. Ge, K. Raab, J. Zázvorka, M.-A. Syskaki, A. Shahee, M. Ruhwedel, T. Böttcher, P. Pirro, G. Jakob, U. Nowak and M. Kläui
  Nat Commun 14, 5424 - published 11. September 2023
  press release​​​​​​​ of the University Konstanz 
   
• Rotationally invariant formulation of spin-lattice coupling in multiscale modeling
  M. Weißenhofer, H. Lange, A. Kamra, S. Mankovsky, S. Polesya, H. Ebert, and U. Nowak
  Phys. Rev. B 108, L060404 – published 23 August 2023
   
• Temperature dependence of current-driven and Brownian skyrmion dynamics in ferrimagnets with compensation point
  M. Weißenhofer and U. Nowak
  Phys. Rev. B. 107, 064423 - published 24 February 2023

2022

• Nutational switching in ferromagnets and antiferromagnets
  L. Winter, S. Großenbach, U. Nowak, and L. Rózsa
  Phys. Rev. B 106, 214403 - published 5 December 2022
  related also to project B06
   
• Walker breakdown of Brownian domain wall dynamics
  M. Weißenhofer, S. Selzer, and U. Nowak
  Phys. Rev. B 106, 104428 – published 26 September 2022
   
• Angular momentum transfer via relativistic spin-lattice coupling from first principles
  S. Mankovsky, S. Polesya, H. Lange, M.s Weißenhofer, U. Nowak, and H. Ebert
  Phys. Rev. Lett. 129, 067202 – published 5 August 2022
   
• Current-induced switching of antiferromagnetic order in Mn2Au from first principles
  S. Selzer, L. Salemi, A. Deák, E. Simon, L. Szunyogh, P. M. Oppeneer, and U. Nowak
  Phys. Rev. B 105, 174416 – published 13 May 2022
   
• Topology dependence of skyrmion Seebeck and skyrmion Nernst effect
  M. Weißenhofer and U. Nowak
  Sci. Rep. 12, 6801 – published 26 April 2022
   
• Magnonic proximity effect in insulating ferromagnetic and antiferromagnetic trilayers
  V. Brehm, M. Evers, U. Ritzmann, and U. Nowak
  Phys. Rev. B 105, 104408 – published 10 March 2022
   
• Polarized phonons carry angular momentum in ultrafast demagnetization
  S. R. Tauchert, M. Volkov, D. Ehberger, D. Kazenwadel, M. Evers, H. Lange, A. Donges, A. Book, W. Kreuzpaintner, U. Nowak, and P. Baum
  Nature, 602, 73 – published 2 February 2022
  related also to projects B05, and B06
  article in campus.kn

2021

• Skyrmion dynamics at finite temperatures: beyond Thiele’s equation
  M. Weißenhofer, L. Rózsa, and U. Nowak
  Phys. Rev. Lett. 127, 047203 – published 22 July 2021
   
• Skyrmions as quasiparticles: Free energy and entropy
  D. Schick, M. Weißenhofer, L. Rózsa, and U. Nowak
  Phys. Rev. B 103, 214417 – published 09 June 2021
   
• Anisotropic skyrmion diffusion controlled by magnetic-field-induced symmetry Breaking
  N. Kerber, M. Weißenhofer, K. Raab, K. Litzius, J. Zázvorka, U. Nowak, and M. Kläui
  Phys. Rev. Applied 15, 044029 (2021) – published 20 April 2021

Futher Publications

• Length Scale of the Spin Seebeck Effect
  A. Kehlberger, U. Ritzmann, D. Hinzke, E.-J. Guo, J. Cramer, G. Jakob, M. C. Onbasli, D. H. Kim, C. A. Ross, M. B. Jungfleisch, B. Hillebrands, U. Nowak, and M. Kläui
  Phys. Rev. Lett. 115, 096602 – published 28 August 2015
   
• Thermally induced magnon accumulation in two-sublattice magnets
  U. Ritzmann, D. Hinzke, and U. Nowak
  Phys. Rev. B 95, 054411 – published 8 February 2017
   
• Magnon detection using a ferroic collinear multilayer spin valve
  J. Cramer, F. Fuhrmann, U. Ritzmann, V. Gall, T. Niizeki, R. Ramos, Z. Qiu, D. Hou, T. Kikkawa, J. Sinova, U. Nowak, E. Saitoh, and M. Kläui 
  Nat. Comm. 9, 1089 - published 14 March 2018
   
• Unveiling domain wall dynamics of ferrimagnets in thermal magnon currents: Competition of angular momentum transfer and entropic torque
  A. Donges, N. Grimm, F. Jakobs, S. Selzer, U. Ritzmann, U. Atxitia, and U. Nowak
  Phys. Rev. Research 2, 013293 – published 11 March 2020