Tomas Jungwirth: Crystal symmetries and transport phenomena in antiferromagnets

The suppression of dipolar fields in antiferromagnets is favorable for high density integration of memory elements and makes them robust against magnetic field perturbations. A related unique merit of antiferromagnetic spintronics is the multi-level memristive switching, suitable for integrating memory with logic or neuromorphic functionalities. Ultra-fast THz spin dynamics is yet another attractive feature of antiferromagnets. In the lecture we will first give a brief overview of these multiple directions in current research of antiferromagnetic spintronics [1]. We will then outline the rich symmetry landscape of antiferromagnets which allows for a range of transport phenomena suitable for manipulating and detecting antiferromagnetic spins. Our main focus will be on electrical readout of spin-reversal in antiferromagnets. This can be facilitated by a second-order magnetoresistance effect in antiferromagnets with broken time and space-inversion symmetries [2]. In the linear response, we introduce a mechanism of the spontaneous Hall effect in collinear antiferromagnets in which the required breaking of time-reversal and other symmetries is caused by the arrangement of non-magnetic atoms in the lattice [3].

Reference:

[1] T. Jungwirth et al., Nature Physics 14, 200 (2018)

[2] J. Godinho et al., Nature Communications 9, 4686 (2018)

[3] L. Šmejkal et al., arXiv:1901.00445