Gate-tunable Strong Spin-orbit Interaction in Two-dimensional Tellurium Probed by Weak-antilocalization

TL;DR

This study demonstrates gate-tunable strong spin-orbit interaction in 2D tellurium films, revealing insights into spin relaxation mechanisms and phase coherence, with potential applications in spintronics.

Contribution

First experimental investigation of conduction band transport in 2D tellurium using dielectric doping and weak-antilocalization analysis.

Findings

Gate-tunable spin-orbit interaction observed.

Transition from weak localization to weak anti-localization with gate bias.

Large phase coherence length of ~600nm at 1K.

Abstract

Tellurium (Te) has attracted great research interest due to its unique crystal structure since 1970s. However, the conduction band of Te is rarely studied experimentally because of the intrinsic p-type nature of Te crystal. By atomic layer deposited dielectric doping technique, we are able to access the conduction band transport properties of Te in a controlled fashion. In this paper, we report on a systematic study of weak-antilocalization (WAL) effect in n-type two-dimensional (2D) Te films. We find that the WAL agrees well with Iordanskii, Lyanda-Geller, and Pikus (ILP) theory. The gate and temperature dependent WAL reveals that Dyakonov-Perel (DP) mechanism is dominant for spin relaxation and phase relaxation is governed by electron-electron (e-e) interaction. Large phase coherence length near 600nm at T=1K is obtained, together with gate tunable spin-orbit interaction (SOI). Transition from weak-localization (WL) to weak-antilocalization (WAL) depending on gate bias is also observed. These results demonstrate that newly developed solution-based synthesized Te films provide a new controllable strong SOI 2D semiconductor with high potential for spintronic applications.