Coherent Spin Amplification Using a Beam Splitter

TL;DR

This paper demonstrates a method to amplify spin polarization in n-type GaAs using a capacitive beam splitter, maintaining coherence and achieving around 50% polarization without relying on strong spin-orbit interaction.

Contribution

It introduces a novel spin amplification technique with a beam splitter in GaAs, preserving coherence and controlling spin polarization precisely.

Findings

Spin polarization amplified to ~50%.

Spin coherence maintained during amplification.

Effective in materials with weak spin-orbit interaction.

Abstract

We report spin amplification using a capacitive beam splitter in n-type GaAs where the spin polarization is monitored via transverse electron focusing measurement. It is shown that partially spin-polarized current injected by the emitter can be precisely controlled and the spin polarization associated with it can be amplified by the beam splitter, such that a considerably high spin polarization of around 50% can be obtained. Additionally, the spin remains coherent as shown by the observation of quantum interference. Our results illustrate that spin polarization amplification can be achieved in materials without strong spin-orbit interaction.