Coherent dynamics in stochastic systems revealed by full counting statistics

TL;DR

This paper introduces a method to identify coherent quantum dynamics within stochastic systems by analyzing full counting statistics, demonstrated through electron transfer in a quantum-dot spin valve, surpassing traditional analysis tools.

Contribution

The authors propose a novel approach to extract coherent dynamics from counting statistics, applicable even when conventional methods fail.

Findings

Coherent dynamics can be isolated from counting statistics.

The method works in regimes where other tools are ineffective.

Application demonstrated on quantum-dot spin valve.

Abstract

Stochastic systems feature, in general, both coherent dynamics and incoherent transitions between different states. We propose a method to identify the coherent part in the full counting statistics for the transitions. The proposal is illustrated for electron transfer through a quantum-dot spin valve, which combines quantum-coherent spin precession with electron tunneling. We show that by counting the number of transferred electrons as a function of time, it is possible to distill out the coherent dynamics from the counting statistics even in transport regimes, in which other tools such as the frequency-dependent current noise and the waiting-time distribution fail.