Effect of inelastic scattering on spin entanglement detection through current noise

TL;DR

This paper investigates how inelastic scattering affects the detection of spin entanglement via current noise measurements, showing that shot noise remains a reliable indicator up to 50% inelastic scattering probability.

Contribution

It introduces a generalized charge-conserving voltage probe model to analyze inelastic scattering effects on spin entanglement detection through shot noise.

Findings

Shot noise measurements effectively characterize spin correlations with up to 50% inelastic scattering.

Higher order cumulants do not provide additional information on spin correlations.

The developed technique applies broadly to systems with voltage probes and spin correlations.

Abstract

We study the effect of inelastic scattering on the spin entanglement detection and discrimination scheme proposed by Egues, Burkard, and Loss [Phys. Rev. Lett. \textbf{89}, 176401 (2002)]. The finite-backscattering beam splitter geometry is supplemented by a phenomenological model for inelastic scattering, the charge-conserving voltage probe model, conveniently generalized to deal with entangled states. We find that the behavior of shot-noise measurements in one of the outgoing leads remains an efficient way to characterize the nature of the non-local spin correlations in the incoming currents for an inelastic scattering probability up to 50%. Higher order cumulants are analyzed, and are found to contain no additional useful information on the spin correlations. The technique we have developed is applicable to a wide range of systems with voltage probes and spin correlations.