Gate-controlled Magnetotransport and Electrostatic Modulation of Magnetism in 2D magnetic semiconductor CrPS$_4$

TL;DR

This study demonstrates gate-controlled magnetotransport in exfoliated CrPS$_4$ layers, revealing tunable magnetic phases and large magnetoconductance, highlighting the potential of 2D magnetic semiconductors with large bandwidth for transistor applications.

Contribution

It shows that CrPS$_4$ with a large bandwidth enables functional FETs and magnetic phase control, advancing 2D magnetic semiconductor technology.

Findings

Magnetoconductance reaches 5000% near conduction threshold.

Gate voltage tunes magnetic states despite multilayer thickness.

CrPS$_4$ exhibits a full magnetic phase diagram including spin-flop and spin-flip phases.

Abstract

Using field-effect transistors (FETs) to explore atomically thin magnetic semiconductors with transport measurements is difficult, because the very narrow bands of most 2D magnetic semiconductors cause carrier localization, preventing transistor operation. Here, we show that exfoliated layers of CrPS$_4$ -- a 2D layered antiferromagnetic semiconductor whose bandwidth approaches 1 eV -- allow the realization of FETs that operate properly down to cryogenic temperature. Using these devices, we perform conductance measurements as a function of temperature and magnetic field, to determine the full magnetic phase diagram, which includes a spin-flop and a spin-flip phase. We find that the magnetoconductance depends strongly on gate voltage, reaching values as high as 5000 % near the threshold for electron conduction. The gate voltage also allows the magnetic states to be tuned, despite the relatively large thickness of the CrPS$_4$ multilayers employed in our study. Our results show the need to employ 2D magnetic semiconductors with sufficiently large bandwidth to realize properly functioning transistors, and identify a candidate material to realize a fully gate-tunable half-metallic conductor.