Recent progress in open quantum systems: Non-Gaussian noise and decoherence in fermionic systems

TL;DR

This paper reviews recent advances in understanding non-Gaussian noise and decoherence in fermionic open quantum systems, highlighting models like quantum telegraph noise and electronic shot noise, with applications to quantum transport and interferometry.

Contribution

It provides new insights into decoherence mechanisms caused by non-Gaussian noise in fermionic systems, including exact solutions for models relevant to quantum transport.

Findings

Decoherence by non-Gaussian noise is significant in nanostructures.

Quantum telegraph noise and shot noise models are essential for understanding fermionic decoherence.

Bosonization and semiclassical methods effectively analyze dephasing in electronic interferometers.

Abstract

We review our recent contributions to two topics that have become of interest in the field of open, dissipative quantum systems: non-Gaussian noise and decoherence in fermionic systems. Decoherence by non-Gaussian noise, i.e. by an environment that cannot be approximated as a bath of harmonic oscillators, is important in nanostructures (e.g. qubits) where there might be strong coupling to a small number of fluctuators. We first revisit the pedagogical example of dephasing by classical telegraph noise. Then we address two models where the quantum nature of the noise becomes essential: "quantum telegraph noise" and dephasing by electronic shot noise. In fermionic systems, many-body aspects and the Pauli principle have to be taken care of when describing the loss of phase coherence. This is relevant in electronic quantum transport through metallic and semiconducting structures. Specifically, we recount our recent results regarding dephasing in a chiral interacting electron liquid, as it is realized in the electronic Mach-Zehnder interferometer. This model can be solved employing the technique of bosonization as well as a physically transparent semiclassical method.