Quantum dynamics in nonequilibrium environments

TL;DR

This paper introduces a formalism to analyze quantum systems interacting with nonequilibrium, non-Gaussian environments, highlighting the role of qubits as detectors and exploring non-Markovian effects in various coupling regimes.

Contribution

It provides a new theoretical framework for understanding quantum dynamics in complex, nonequilibrium environments, including classical and quantum influences.

Findings

Qubits can effectively detect environmental fluctuation statistics.

Non-Markovian effects are significant in both weak and strong coupling regimes.

The formalism is applied to charge qubits in quantum dot systems.

Abstract

We present a formalism for studying the behaviour of quantum systems coupled to nonequilibrium environments exhibiting nonGaussian fluctuations. We discuss the role of a qubit as a detector of the statistics of environmental fluctuations, as well as nonMarkovian effects in both weak and strong coupling limits. We also discuss the differences between the influences of classical and quantum environments. As examples of the application of this formalism we study the dephasing and relaxation of a charge qubit coupled to nonequillibrium electron transport through single and double quantum dots.