Anomalous Nonlinear Magnetoconductivity in van der Waals Magnet CrSBr

TL;DR

This paper reports the discovery of an anomalous nonlinear magnetoconductivity in van der Waals magnet CrSBr, controlled by internal magnetic order parameters, with potential applications in high-frequency rectification and magnetic state readout.

Contribution

It demonstrates a novel anomalous NLMC in CrSBr heterostructures, tunable by magnetic states, driven by Berry connection polarizability, expanding the functional scope of nonlinear magnetotransport.

Findings

Anomalous NLMC observed in CrSBr heterostructures with broken inversion and time-reversal symmetry.

The NLMC can be switched between multiple states in ferromagnetic and antiferromagnetic configurations.

The signal magnitude is three orders higher in ferromagnetic and one order higher in antiferromagnetic states compared to previous reports.

Abstract

Nonlinear magnetoconductivity (NLMC) is a nonreciprocal transport response arising in non-centrosymmetric materials. However, this ordinary NLMC signal vanishes at zero magnetic field, limiting its potential for applications. Here, we report the observation of an anomalous NLMC controlled by internal order parameters such as the magnetization or N\'eel vectors. We achieve this response by breaking both inversion and time-reversal symmetry in artificial van der Waals heterostructures based on the magnetic CrSBr and insulating hBN. The nonreciprocal signal can be tuned between two different states in ferromagnetic monolayer CrSBr and among four different states in antiferromagnetic bilayer CrSBr, thanks to its metamagnetic transition. Remarkably, this output signal in the ferromagnetic (antiferromagnetic) state of CrSBr is three (one) orders of magnitude higher than those previously measured. A conductivity scaling analysis reveals the Berry connection polarizability as the origin of the anomalous NLMC. Our results pave the way for high-frequency rectifiers with magnetically switchable output polarity as well as for an efficient electrical readout of the magnetic state of antiferromagnetic materials.