Can dephasing generate non-local spin correlations?

TL;DR

This paper investigates how dephasing affects non-local spin correlations in a non-adiabatic spin pump, revealing that incoherent transport can reverse correlation signs, with dephasing ultimately producing positive correlations.

Contribution

It demonstrates that incoherent transport can change non-local spin shot noise correlations from anti-correlated to correlated, and explores how dephasing influences these quantum spin correlations.

Findings

Incoherent transport can reverse non-local spin shot noise correlations.

Third moment remains robust under incoherent transport.

Maximal dephasing leads to positive non-local spin correlations.

Abstract

By examining the full counting statistics of a non adiabatic pure spin pump with particular emphasis on the second and third moments, it is shown that incoherent or sequential transport, in contrast to coherent transport, can change non-local spin shot noise cross-correlations from being anti-correlated to being completely correlated, a truly counterintuitive result. The third moment on the other hand is shown to be much more resilient and its nature remains unaltered in incoherent transport regime. However, phenomenologically including dephasing modifies this picture as both Shot noise and more so the third moment are non-trivially affected. In fact non-local spin correlations are completely positive for maximal dephasing.