Rashba Spin-Orbit Coupling and Nonlocal Correlations in Disordered 2D Systems

TL;DR

This paper extends the dynamical cluster approximation to include Rashba spin-orbit coupling, enabling efficient study of disorder and nonlocal correlations in 2D systems, with results validated against exact methods.

Contribution

It introduces a novel DCA extension that incorporates Rashba SOC, allowing for the exploration of complex interplay between disorder, SOC, and correlations in low-dimensional systems.

Findings

Rashba SOC and nonlocal correlations significantly alter single-particle properties.

The method captures key features of the symplectic universality class.

Good agreement with kernel polynomial method benchmarks.

Abstract

We present an extension of the dynamical cluster approximation (DCA) that incorporates Rashba spin-orbit coupling (SOC) to investigate the interplay between disorder, spin-orbit interaction, and nonlocal spatial correlations in disordered two-dimensional systems. By analyzing the average density of states, momentum-resolved self-energy, and return probability, we demonstrate how Rashba SOC and nonlocal correlations jointly modify single-particle properties and spin-dependent interference. The method captures key features of the symplectic universality class, including SOC-induced delocalization signatures at finite times. We benchmark the DCA results against those obtained from the numerically exact kernel polynomial method, finding good agreement. This validates the computationally efficient, mean-field-based DCA framework as a robust tool for exploring disorder, spin-orbit coupling, and nonlocal correlation effects in low-dimensional systems, and paves the way for simulating multiorbital and strongly correlated systems that were previously inaccessible due to computational limitations.