Topological Hall effect and skew scattering of non-polarized electrons

by Prof. Igor Rozhansky

Ioffe Institute St.Peterburg Russia

at Condensed Matter Seminar

Mon, 28 Nov 2022, 11:10
Sacta-Rashi Building for Physics (54), room 207

Abstract

A combination of spin-orbit coupling and breaking of time reversal symmetry gives rise to plenty of physical phenomena of a fundamental interest and attractive for spintronic applications. A vivid example is the anomalous Hall effect (AHE) and more recently discovered topological Hall effect (THE) considered to be useful in spintronic sensors and information technology. Both AHE and THE are usually based on the spin Hall effect and, hence, require macroscopic spin polarization of the charge carriers to produce an electrical response due to time reversal symmetry breaking requirement. However, the time reversal symmetry breaking can originate from scatterers rather than from incident electrons. Then an asymmetrical scattering and, consequently, transverse electrical current become possible even for non-polarized electrons. The advantage of this idea is that it allows for an all-electrical read-out of a magnetic state and magnetisation sensing with a non-polarized electrical current. The talk covers two distinct examples of such a case. The first one is the THE for magnetic skyrmions, We have developed a theory describing THE in a weak coupling regime demonstrating the emergence of a transverse electrical response for non-polarized current flowing through the skyrmionic system. Another phenomenon based on the similar theoretical grounds is a skew scattering of electrons on paramagnetic centers in semiconductors, it leads to the contribution to the AHE independent of the spin polarization of the mobile charge carriers and some other interesting consequences.

Created on 10-11-2022 by Meidan, Dganit (dganit)
Updaded on 26-11-2022 by Meidan, Dganit (dganit)