Magnetism-Induced Band-Edge Shift as the Mechanism for Magnetoconductance in CrPS₄ Transistors.

Abstract

Transistors realized on the 2D antiferromagnetic semiconductor CrPS₄ exhibit large magnetoconductance due to magnetic-field-induced changes in the magnetic state. The microscopic mechanism coupling the conductance and magnetic state is not understood. We identify it by analyzing the evolution of the parameters determining the transistor behavior─carrier mobility and threshold voltage─with temperature and magnetic field. For temperatures <i>T</i> near the <i>Néel</i> temperature <i>T</i>_N, the magnetoconductance originates from a mobility increase due to the applied magnetic field that reduces spin fluctuation induced disorder. For <i>T</i> ≪ <i>T</i>_N, instead, what changes is the threshold voltage, so that increasing the field at fixed gate voltage increases the density of accumulated electrons. The phenomenon is explained by a conduction band-edge shift correctly predicted by the <i>ab initio</i> calculations. Our results demonstrate that the band structure of CrPS₄ depends on its magnetic state and reveal a mechanism for magnetoconductance that had not been identified earlier.