Rashba effect in quantum networks

TL;DR

This paper develops a formalism to analyze quantum networks with Rashba spin-orbit coupling and magnetic fields, revealing how these factors induce localization and affect conductance through quantum interference effects.

Contribution

It introduces a new scattering formalism for studying transport in quantum networks with spin-orbit coupling and magnetic fields, highlighting localization phenomena.

Findings

Magnetic field and Rashba coupling can induce electron localization.

Conductance suppression occurs at specific spin-orbit and magnetic field values.

Interplay between Aharonov-Bohm and non-Abelian phases affects transport.

Abstract

We present a formalism to study quantum networks made up by single-channel quantum wires in the presence of Rashba spin-orbit coupling and magnetic field. In particular, linear transport through one-dimensional and two-dimensional finite-size networks is studied by means of the scattering formalism. In some particular quantum networks, the action of the magnetic field or of the Rashba spin-orbit coupling induces localization of the electron wave function. This phenomenon, which relies on both the quantum-mechanical interference and the geometry of the network, is manifested through the suppression of the conductance for specific values of the spin-orbit-coupling strength or of the magnetic field. Furthermore, the interplay of the Aharonov-Bohm phases and of the non-Abelian phases introduced by spin-orbit coupling, is discussed in a number of cases.