Symmetry-Driven Electrical Switching of Anisotropic Skyrmion Hall Effect in Altermagnets

TL;DR

This paper presents a novel electrical method to reversibly control the anisotropic skyrmion Hall effect in two-dimensional altermagnets, enabling precise skyrmion transport without magnetic fields.

Contribution

It introduces a symmetry-based approach to electrically switch the SkHE in altermagnets, demonstrated through first-principles and spin model simulations in monolayer CaMnSn.

Findings

Electric field can invert the SkHE in altermagnets.

Anisotropic SkHE depends on current direction relative to crystal axes.

Reversible control of skyrmion transport achieved without magnetic fields.

Abstract

Controlling the skyrmion Hall effect (SkHE) is pivotal for developing topological spintronics but typically relies on magnetic field reversal. Here, we demonstrate a general strategy for the purely electrical switching of the SkHE in two-dimensional altermagnets. Through symmetry and model analysis, we reveal that the intrinsic altermagnetic symmetry imposes sublattice-dependent anisotropic exchange and Dzyaloshinskii-Moriya interactions. These interactions induce a highly anisotropic SkHE, where the transverse velocity is strictly dictated by the current direction relative to the crystal axes. Crucially, we show that an external electric field can strongly modulate these interaction parameters by inversing the altermagnetic symmetry, allowing for the reversible inversion of the anisotropic SkHE. Using first-principles and atomistic spin model simulations, this mechanism is further demonstrated in monolayer CaMnSn. Our study establishes a unique strategy for realizing precise, electrically tunable skyrmion transport without magnetic fields.