Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU
Professor Bertrand Dupé
Prof Stephen Blundell
Abstract
Magnetic skyrmions are localized, non-collinear chiral magnetic textures which are envisioned to play a major role in spintronics [1], neuromorphic computing [2] and quantum computing [3] applications. Thanks to their topological properties that enhance their stability, ferromagnetic (FM) skyrmions in metals have been subjected to intense research in metals since the last 10 years.
Recently, antiferromagnetic (AFM) topological magnetic structures have been explored such as bi-meron or AFM-skyrmions in insulators [4]. Antiferromagnetic (AFM) skyrmions have drawn attention due to their fast dynamics and their robustness against stray fields [5]. In particular, AFM skyrmion are characterized by a non-zero winding number associated to the AFM vector L. Although AFM skyrmions in a synthetic antiferromagnet have recently been reported, they are still elusive in single-phase antiferromagnets.
Here, we first review the different stabilization and nucleation mechanisms of skyrmions in metals [6–8]. We especially focus on the different algorithm implemented in our home-made code Matjes to obtain ground states of topologically protected magnetic textures [9]. We explore also the dynamics of these magnetic textures via different external stimuli such spin torques or laser pulses.
Finally, via density functional theory, we explore the magnetic ground state of the AFM multiferroics BiFeO3 as a function of symmetry and strain [8] and show that – in multiferroic - new coupling terms my emerge and have a significant impact on the symmetry of topological objects. These findings open up the possibility to stabilize both ferroelectrics and magnetic skyrmions in multiferroics [10–12].
References:
[1] C. Back et al., J. Phys. D Appl. Phys. 53, 363001 (2020).
[2] J. Grollier et al., Nat. Electron. 3, 360 (2020).
[3] G. Yang, P. Stano, J. Klinovaja, and D. Loss, Phys. Rev. B: Condens. Matter Mater. Phys. 93, 224505 (2016).
[4] H. Jani et al., Nature 590, 74 (2021).
[5] X. Zhang et al., Sci. Rep. 6, 24795 (2016).
[6] B. Dupé et al., Nat. Commun. 5, 4030 (2014).
[7] B. Dupé et al., Nat. Commun. 7, 11779 (2016).
[8] L. Desplat et al., Phys. Rev. B Condens. Matter 104, L060409 (2021).
[9] P.M. Buhl, L. Desplat, M. Boettcher, S. Meyer, & B. Dupé, Matjes: https://doi.org/10.5281/zenodo.12685461 (2024).
[10] B. Xu et al., Phys. Rev. B Condens. Matter 103, 214423 (2021).
[11] S. Meyer et al., Phys. Rev. B Condens. Matter 108, 024403 (2023).
[12] S. Meyer et al., Phys. Rev. B Condens. Matter 109, 184431 (2024).