Ultrathin SnTe films as a route towards all-in-one spintronics devices

TL;DR

This paper proposes ultrathin SnTe films as a promising platform for all-in-one spintronics devices, leveraging intrinsic spin textures and electric field control to enhance spin lifetime and conductivity without ferromagnets.

Contribution

It introduces a novel all-electric spin device based on 2D SnTe that utilizes persistent spin textures and electric field tuning, advancing spintronics technology.

Findings

Persistent spin texture (PST) exists in ferroelectric 2D SnTe.

Electric fields can modulate spin lifetime by detuning spin wave modes.

Ultrathin SnTe films show enhanced spin Hall conductivity.

Abstract

Spin transistors based on a semiconducting channel attached to ferromagnetic electrodes suffer from fast spin decay and extremely low spin injection/detection efficiencies. Here, we propose an alternative all-in-one spin device whose operation principle relies on electric manipulation of the spin lifetime in two-dimensional (2D) SnTe, in which the sizable spin Hall effect eliminates the need for using ferromagnets. In particular, we explore the persistent spin texture (PST) intrinsically present in the ferroelectric phase which protects the spin from decoherence and supports extraordinarily long spin lifetime. Our first-principles calculations followed by symmetry arguments revealed that such a spin wave mode can be externally detuned by perpendicular electric field, leading to spin randomization and decrease in spin lifetime. We further extend our analysis to ultrathin SnTe films and confirm the emergence of PST as well as a moderate enhancement of intrinsic spin Hall conductivity. The recent room-temperature observation of the ferroelectric phase in 2D-SnTe suggests that novel all-electric spintronics devices are within reach.