Towards exact predictions of spin-phonon relaxation times: an ab initio implementation of open quantum systems theory

TL;DR

This paper presents an ab initio approach combining quantum master equations and electronic structure methods to accurately predict spin-phonon relaxation times in solid-state materials, bridging theory and experiment.

Contribution

It introduces a fully ab initio implementation of spin relaxation theory using advanced quantum master equations and electronic structure calculations.

Findings

Excellent agreement with experimental relaxation times.

Universal applicability across different transition metal and lanthanide compounds.

Demonstrates predictive power of the new theoretical framework.

Abstract

Spin-phonon coupling is the main drive of spin relaxation and decoherence in solid-state semiconductors at finite temperature. Controlling this interaction is a central problem for many disciplines, ranging from magnetic resonance to quantum technologies. Spin relaxation theories have been developed for almost a century but often employ a phenomenological description of phonons and their coupling to spin, resulting in a non-predictive tool and hindering our detailed understanding of spin dynamics. Here we combine fourth-order time-local quantum master equations with advanced electronic structure methods and perform predictions of spin-phonon relaxation time for a series of solid-state coordination compounds based on both transition metals and lanthanide Kramers ions. The agreement between experiments and simulations demonstrates that an accurate, universal and fully ab initio implementation of spin relaxation theory is possible, thus paving the way to a systematic study of spin-phonon relaxation in solid-state materials.