Phonon distributions of a single bath mode coupled to a quantum dot

TL;DR

This paper investigates the non-thermal phonon distribution in a single mode bath coupled to a quantum dot, revealing unique population behaviors and sub-Poissonian statistics influenced by electron transport and double occupancy.

Contribution

It introduces a detailed analysis of out-of-equilibrium phonon distributions in a quantum dot system within the rotating wave approximation, highlighting novel population effects and statistical properties.

Findings

Phonon distribution becomes non-thermal and selectively populated.

Sub-Poissonian phonon statistics are observed under certain conditions.

Double occupancy of the quantum dot favors sub-Poissonian behavior.

Abstract

The properties of an unconventional, single mode phonon bath coupled to a quantum dot, are investigated within the rotating wave approximation. The electron current through the dot induces an out of equilibrium bath, with a phonon distribution qualitatively different from the thermal one. In selected transport regimes, such a distribution is characterized by a peculiar selective population of few phonon modes and can exhibit a sub-Poissonian behavior. It is shown that such a sub-Poissonian behavior is favored by a double occupancy of the dot. The crossover from a unequilibrated to a conventional thermal bath is explored, and the limitations of the rotating wave approximation are discussed.