Spin relaxation in hole-doped transition metal dichalcogenide monolayer and bilayer with the crystal defects

TL;DR

This study investigates spin relaxation in hole-doped transition-metal dichalcogenide monolayers and bilayers with crystal defects, revealing long relaxation times in monolayers due to symmetry effects and shorter times in bilayers.

Contribution

It provides a realistic estimation of spin relaxation rates considering lattice vacancies using a multi-orbital tight-binding model, highlighting the role of symmetry in spin dynamics.

Findings

Monolayer TMDs exhibit extremely long spin relaxation times.

Bilayer TMDs have significantly shorter spin relaxation times.

Mirror reflection symmetry suppresses spin hybridization in monolayers.

Abstract

We study the electronic spin relaxation effect in the hole-doped monolayer and bilayer transition-metal dichalcogenides in the presence of the crystal defects. We consider realistic models of the lattice vacancy and actually estimate the spin relaxation rate using the multi-orbital tight-binding model. In the monolayer, the spin-relaxation time is found to be extremely long compared to the momentum relaxation time, and this is attributed to the fact that the spin hybridization in the band structure is suppressed by the mirror reflection symmetry. The bilayer TMD has a much shorter spin relaxation time in contrast, and this is attributed to stronger spin hybridization due to the absence of the mirror symmetry.