Nonlinear field dependence of Hall effect and high-mobility multi-carrier transport in an altermagnet CrSb

TL;DR

This study reveals the complex multi-carrier transport and nonlinear Hall effect in CrSb, highlighting its potential for spintronics due to high mobility and unique electronic properties.

Contribution

It provides the first comprehensive analysis of CrSb's electronic transport, demonstrating multi-carrier effects and nonlinear Hall behavior in an altermagnet.

Findings

CrSb exhibits large, positive, non-saturated magnetoresistance obeying Kohler's rule.

The Hall effect shows nonlinear magnetic field dependence over a wide temperature range.

A three-carrier model accurately fits the conductivity data, indicating semimetallic behavior.

Abstract

As a promising candidate for altermagnet, CrSb possesses a distinctive compensated spin split band structure that could bring groundbreaking concepts to the field of spintronics. In this work, we have grown high-quality CrSb single crystals and comprehensively investigated their electronic and magneto-transport properties. We have observed large, positive, and non-saturated magnetoresistance (MR) in CrSb, which well obeys Kohler's rule, indicating its classic Lorentz scattering origins. Remarkably, a nonlinear magnetic field dependence of Hall effect resembling the spontaneous anomalous Hall is identified over a wide temperature range. After careful analysis of the transport data, we conclude the non-linearity mainly stems from the incorporation of different carriers in the magnetoconductivity. According to the Fermi surface analyses of CrSb, we applied the three-carrier model to fit the conductivity data, yielding good agreement. The extracted carrier concentration and mobility indicates that CrSb behaves more like a semimetal, with the highest mobility reaching 3*103 cm2V-1s-1. Furthermore, calculations using the semiclassical Boltzmann transport theory have successfully reproduced the main features of the experimental MR and Hall effect in CrSb. These exceptional transport properties make CrSb unique for applications in spintronics as an altermagnet.