Probing entanglement via Rashba-induced shot noise oscillations

TL;DR

This paper explores how Rashba spin-orbit interaction influences shot noise in electron pairs, revealing oscillations that distinguish entangled states and enable spin control, with potential applications in spin transistors.

Contribution

It introduces a simplified method for calculating shot noise in systems with Rashba interaction, highlighting how noise oscillations can identify entangled states and measure spin-orbit coupling.

Findings

Shot noise exhibits continuous bunching and antibunching behaviors.

Distinct shot noise oscillations differentiate entangled and unentangled triplet states.

Additional modulation from spin-orbit interband mixing enables advanced spin transistor design.

Abstract

We have recently calculated shot noise for entangled and spin-polarized electrons in novel beam-splitter geometries with a local Rashba s-o interaction in the incoming leads. This interaction allows for a gate-controlled rotation of the incoming electron spins. Here we present an alternate simpler route to the shot noise calculation in the above work and focus on only electron pairs. Shot noise for these shows continuous bunching and antibunching behaviors. In addition, entangled and unentangled triplets yield distinctive shot noise oscillations. Besides allowing for a direct way to identify triplet and singlet states, these oscillations can be used to extract s-o coupling constants through noise measurements. Incoming leads with spin-orbit interband mixing give rise an additional modulation of the current noise. This extra rotation allows the design of a spin transistor with enhanced spin control.