Tunneling between 2D electron layers with correlated disorder: anomalous sensitivity to spin-orbit coupling

TL;DR

This paper theoretically investigates tunneling between two 2D electron layers with correlated disorder, revealing how spin-orbit coupling influences tunneling characteristics and offers a method to measure weak spin-orbit effects.

Contribution

It introduces a novel theoretical framework for understanding tunneling in correlated disordered 2D layers and links spin-orbit coupling to observable tunneling features.

Findings

Correlated disorder causes eigenstates to be nearly orthogonal, shifting the tunneling peak.

Complete disorder correlation makes the peak sensitive to spin-orbit coupling.

The study suggests a way to measure weak spin-orbit splitting via tunneling experiments.

Abstract

Tunneling between two-dimensional electron layers with mutually correlated disorder potentials is studied theoretically. Due to this correlation, the diffusive eigenstates in different layers are almost orthogonal to each other. As a result, a peak in the tunnel I-V characteristics shifts towards small bias, V. This "protects" the peak against the interaction-induced smearing, since the relaxation rate near the Fermi level is low. If the correlation in disorder potentials is complete, the peak position and width are governed by the spin-orbit coupling in the layers; this coupling lifts the orthogonality of the eigenstates. Possibility to use inter-layer tunneling for experimental determination of weak intrinsic spin-orbit splitting of the Fermi surface is discussed.