- Dmitry Sokolov: Metamagnetic textures in non-centrosymmetric antiferromagnets
- 6. 11. 2019, 14:10
- lecture room F2, first floor Ke Karlovu 5
- more information
Abstract:
Spin-orbit coupling drives an array of phenomena in condensed matter physics ranging from Rashba surface states to the magnetic skyrmion in certain non-centrosymmetric compounds [1]. The latter attracted a considerable interest in the recent years due to their magnetic vortex-like nature, but also due to potential applications in spintronics [2]. So far the majority of magnetic skyrmions were observed in restricted regions of magnetic field-temperature phase diagram of chiral ferromagnets, in which strong spin-orbit coupling twists
the ferromagnetic order parameter into a long wavelength spiral. I will present a case of non-centrosymmetric antiferromagnet Ca3Ru2O7, in which the Lifshitz invariants, as expression of the spin-orbit coupling-driven antisymmetric magnetic exchange, couple the antiferromagnetic order parameter to the applied magnetic field and stabilise the 1-dimensional spin spiral. Via neutron diffraction and small-angle neutron scattering measurements I have recently showed that Ca3Ru2O7 spatially oscillates between ferro- and antiferromagnetic configurations resulting in a so-called metamagnetic textured state [3]. The textured state also shows a strong anomalous Hall effect component indicating a topological nature of these spin-configurations[4]. I will also suggest materials, in which Lifshitz invariants may couple many magnetic modes, which leads to materials hosting lumps of magnetic order, which can condense without conventional long-range order into disordered phases of magnetic skyrmions or other spin textures, or can form classical chiral spin liquids.
[1] A. Soumyanarayanan, N. Reyren, A. Fert, and C. Panagopoulos, Nature 539, 509 (2016).
[2] T. Jungwirth, J. Sinova, A. Manchon, X. Marti, J. Wunderlich and C. Felser, Nat. Phys. 14, 200 (2018).
[3] D. A. Sokolov et al., Nat. Phys. 15, 671 (2019).
[4] N. Nagaosa, J. Sinova, S. Onoda, A. H. MacDonald, and N. P. Ong, Rev. Mod. Phys. 82, 1539 (2010).
<">https://www.staffmail.ed.ac.uk/imp/compose.php?to=andy.mackenzie%40cpfs.mpg.de>