Thermal Effects on Photon-Induced Quantum Transport

TL;DR

This paper models how thermal effects influence laser-induced quantum transport in a quantum dot, revealing how temperature impacts coherence, occupation, and photocurrent dynamics through a nonequilibrium Green function approach.

Contribution

It introduces a theoretical framework incorporating thermal effects into photon-induced quantum transport analysis using nonequilibrium Green functions.

Findings

Thermal fluctuations reduce Rabi oscillation amplitude.

Photocurrent can switch sign over time due to thermal and photon interactions.

Stationary photocurrent maximized by tuning laser intensity.

Abstract

We theoretically investigate laser induced quantum transport in a two-level quantum dot attached to electric contacts. Our approach, based on nonequilibrium Green function technique, allows to include thermal effects on the photon-induced quantum transport and excitonic coherent dynamics. By solving a set of coupled integrodifferential equations, involving correlation and propagator functions, we obtain the photocurrent and the dot occupations as a function of time. The characteristic coherent Rabi oscillations are found in both occupations and photocurrent, with two distinct sources of decoherence: incoherent tunneling and thermal fluctuations. In particular, for increasing temperature the dot becomes more thermally occupied which shrinks the amplitude of the Rabi oscillations, due to Pauli blockade. Finally, due to the interplay between photon and thermal induced electron populations, the photocurrent can switch sign as time evolves and its stationary value can be maximized by tunning the laser intensity.