Spin-orbit related power-law dependence of the diffusive conductivity on the carrier density in disordered Rashba two-dimensional electron systems

TL;DR

This study reveals a power-law relationship between diffusive conductivity and carrier density in disordered Rashba 2D electron systems, with the exponent linearly dependent on Rashba strength, highlighting the influence of spin-orbit coupling on charge transport.

Contribution

The paper introduces a non-perturbative numerical approach to analyze disorder effects, uncovering a novel power-law dependence of conductivity on carrier density in Rashba systems.

Findings

Power-law dependence of conductivity on carrier density.

Exponent depends linearly on Rashba strength.

Behavior observable in tunable Rashba systems.

Abstract

By using the momentum-space Lanczos recursive method which considers rigorously all multiple-scattering events, we unveil that the non-perturbative disorder effect has dramatic impact on the charge transport of a two-dimensional electron system with Rashba spin-orbit coupling in the low-density region. Our simulations find a power-law dependence of the dc longitudinal conductivity on the carrier density, with the exponent linearly dependent on the Rashba spin-orbit strength but independent of the disorder strength. Therefore, the classical charge transport influenced by complicated multiple-scattering processes also shows the characteristic feature of the spin-orbit coupling. This highly unconventional behavior is argued to be observable in systems with tunable carrier density and Rashba splitting, such as the LaAlO$_{3}$/SrTiO$_{3}$ interface, the heterostructure of Rashba semiconductors bismuth tellurohalides and the surface alloy Bi$_x$Pb$_y$Sb$_{1-x-y}$/Ag(111).