Spin-phonon relaxation from a universal \emph{ab initio} density-matrix approach

TL;DR

This paper introduces a universal first-principles method based on Lindbladian dynamics to accurately predict spin relaxation times in solids, accounting for various mechanisms and symmetries, with strong experimental agreement.

Contribution

The authors develop a novel, comprehensive ab initio approach to calculate spin-phonon relaxation times, unifying different relaxation mechanisms and symmetry considerations.

Findings

Spin relaxation times decrease with temperature.

D'yakonov-Perel' mechanism shows inverse relation with extrinsic scattering.

Large anisotropy predicted in transition metal dichalcogenides.

Abstract

Designing new quantum materials with long-lived electron spin states urgently requires a general theoretical formalism and computational technique to reliably predict intrinsic spin relaxation times. We present a new, accurate and universal first-principles methodology based on Lindbladian dynamics of density matrices to calculate spin-phonon relaxation time ($\tau_s$) of solids with arbitrary spin mixing and crystal symmetry. This method describes contributions of Elliott-Yafet (EY) and D'yakonov-Perel' (DP) mechanisms to spin relaxation for systems with and without inversion symmetry on an equal footing. We show that intrinsic spin and momentum relaxation times both decrease with increasing temperature; however, for the DP mechanism, spin relaxation time varies inversely with extrinsic scattering time. We predict large anisotropy of spin lifetime in transition metal dichalcogenides. The excellent agreement with experiments for a broad range of materials underscores the predictive capability of our method for properties critical to quantum information science.