Full Counting Statistics of Spin Currents

TL;DR

This paper develops a framework for analyzing the full counting statistics of spin currents, highlighting the quantum dynamics of detectors and their impact on measurement outcomes.

Contribution

It introduces a method to derive full counting statistics of spin transfers considering multiple detectors and quantum effects, challenging classical measurement assumptions.

Findings

Statistics depend on quantum detector dynamics.

Multiple detectors can monitor different spin components simultaneously.

Classical projection postulate is insufficient to explain measurement outcomes.

Abstract

We discuss how to detect fluctuating spin currents and derive full counting statistics of electron spin transfers. It is interesting to consider several detectors in series that simultaneously monitor different components of the spins transferred. We have found that in general the statistics of the measurement outcomes cannot be explained with the projection postulate and essentially depends on the quantum dynamics of the detectors.