Rashba spin-orbit interaction and shot noise for spin-polarized and entangled electrons

TL;DR

This paper investigates how Rashba spin-orbit interaction influences shot noise in a four-probe setup, revealing oscillations, spin control, and methods to measure the Rashba coupling through noise analysis.

Contribution

It introduces a scattering formalism to analyze shot noise with Rashba interaction, showing how entangled and triplet states can be distinguished and how the Fano factor relates to Rashba coupling.

Findings

Shot noise shows Rashba-induced oscillations with bunching and antibunching.

Entangled and triplet states can be identified via their Rashba phase.

The Fano factor can be used to measure the Rashba coupling constant.

Abstract

We study shot noise for spin-polarized currents and entangled electron pairs in a four-probe (beam splitter) geometry with a local Rashba spin-orbit (s-o) interaction in the incoming leads. Within the scattering formalism we find that shot noise exhibits Rashba-induced oscillations with continuous bunching and antibunching. We show that entangled states and triplet states can be identified via their Rashba phase in noise measurements. For two-channel leads we find an additional spin rotation due to s-o induced interband coupling which provides enhanced spin control. We show that the s-o interaction determines the Fano factor which provides a direct way to measure the Rashba coupling constant via noise.