The Fano-Rashba effect

TL;DR

This paper investigates the Fano-Rashba effect in semiconductor quantum wires, demonstrating how local Rashba spin-orbit interaction induces Fano lineshapes in conductance through quasi bound states interference.

Contribution

It introduces the concept of the Fano-Rashba effect and provides both numerical and analytical solutions to understand conductance features in quantum wires with Rashba interaction.

Findings

Fano lineshapes appear in conductance due to quasi bound states.

The coupled-channel model accurately describes the Fano-Rashba effect.

Numerical solutions validate the analytical ansatz approach.

Abstract

We analyze the linear conductance of a semiconductor quantum wire containing a region where a local Rashba spin-orbit interaction is present. We show that Fano lineshapes appear in the conductance due to the formation of quasi bound states which interfere with the direct transmission along the wire, a mechanism that we term the Fano-Rashba effect. We obtain the numerical solution of the full Schr\"odinger equation using the quantum-transmitting-boundary method. The theoretical analysis is performed using the coupled-channel model, finding an analytical solution by ansatz. The complete numerical solution of the coupled-channel equations is also discussed, showing the validity of the ansatz approach.