Tunable spin-orbit coupling in two-dimensional InSe

TL;DR

This paper shows that the spin-orbit coupling in few-layer InSe can be electrically tuned, enabling potential applications in spintronics, with theoretical modeling validated by experimental measurements.

Contribution

It introduces a hybrid theoretical model to quantify tunable SOC in InSe and validates it through experimental weak antilocalization measurements.

Findings

SOC strength can be widely tuned by electric fields and film thickness.

Theoretical predictions agree well with experimental data.

Potential for electrically switchable spintronic devices.

Abstract

We demonstrate that spin-orbit coupling (SOC) strength for electrons near the conduction band edge in few-layer $\gamma$-InSe films can be tuned over a wide range. This tunability is the result of a competition between film-thickness-dependent intrinsic and electric-field-induced SOC, potentially, allowing for electrically switchable spintronic devices. Using a hybrid $\mathbf{k\cdot p}$ tight-binding model, fully parameterized with the help of density functional theory computations, we quantify SOC strength for various geometries of InSe-based field-effect transistors. The theoretically computed SOC strengths are compared with the results of weak antilocalization measurements on dual-gated multilayer InSe films, interpreted in terms of Dyakonov-Perel spin relaxation due to SOC, showing a good agreement between theory and experiment.