Intermediate anomalous Hall states induced by noncollinear spin structure in magnetic topological insulator MnBi2Te4

TL;DR

This paper reveals intermediate anomalous Hall states in MnBi2Te4 caused by noncollinear spin structures, demonstrating multiple magnetic memory states that can be controlled, with implications for spintronic applications.

Contribution

It uncovers the existence of multiple magnetic memory states in MnBi2Te4 linked to noncollinear spin structures and their controllability, advancing understanding of topological and magnetic interplay.

Findings

Identification of four distinguishable magnetic memory states.

Dependence of intermediate states on gate voltage and temperature.

Ability to switch magnetic states using magnetic field pulses.

Abstract

The combination of topology and magnetism is attractive to produce exotic quantum matters, such as the quantum anomalous Hall state, axion insulators and the magnetic Weyl semimetals. MnBi2Te4, as an intrinsic magnetic topological insulator, provides a platform for the realization of various topological phases. Here we report the intermediate Hall steps in the magnetic hysteresis of MnBi2Te4, where four distinguishable magnetic memory states at zero magnetic field are revealed. The gate and temperature dependence of the magnetic intermediate states indicates the noncollinear spin structure in MnBi2Te4, which can be attributed to the Dzyaloshinskii-Moriya interaction as the coexistence of strong spin-orbit coupling and local inversion symmetry breaking on the surface. Moreover, these multiple magnetic memory states can be programmatically switched among each other through applying designed pulses of magnetic field. Our results provide new insights of the influence of bulk topology on the magnetic states, and the multiple memory states should be promising for spintronic devices.