# Phase coherent transport in bilayer and trilayer MoS2

## TL;DR

This study investigates phase-coherent transport in mono-, bi-, and tri-layer MoS2, revealing dominant D'yakonov-Perel spin relaxation mechanism and no electric-field induced changes in spin-orbit coupling, indicating weak interlayer coupling.

## Contribution

It provides experimental insights into spin relaxation mechanisms and electric field effects in multilayer MoS2, showing multilayers behave like decoupled monolayers.

## Key findings

- Spin relaxation time inversely proportional to momentum relaxation time.
- No electric-field induced change in spin-orbit coupling.
- Multilayer MoS2 behaves as decoupled monolayers.

## Abstract

Bilayer MoS2 is a centrosymmetric semiconductor with degenerate spin states in the six valleys at the corners of the Brillouin zone. It has been proposed that breaking of this inversion symmetry by an out-of-plane electric field breaks this degeneracy, allowing for spin and valley lifetimes to be manipulated electrically in bilayer MoS2 with an electric field. In this work, we report phase-coherent transport properties of double-gated mono-, bi-, and tri-layer MoS2. We observe a similar crossover from weak localization to weak anti-localization, from which we extract the spin relaxation time as a function of both electric field and temperature. We find that the spin relaxation time is inversely proportional to momentum relaxation time, indicating that D'yakonov-Perel mechanism is dominant in all devices despite its centrosymmetry. Further, we found no evidence of electric-field induced changes in spin-orbit coupling strength. This suggests that the interlayer coupling is sufficiently weak and that electron-doped dichalcogenide multilayers behave electrically as decoupled monolayers.

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Source: https://tomesphere.com/paper/1904.08597