Photovoltaic Current Response of Mesoscopic Conductors to Quantized Cavity Modes

TL;DR

This paper investigates how quantized electromagnetic cavity modes induce photovoltaic currents in mesoscopic conductors, revealing dependence on photon occupation and thermal conditions, with potential measurable effects at the picoampere level.

Contribution

It extends previous models to include field quantization effects, analyzing PV current generation in mesoscopic systems with quantum cavity modes, especially in chaotic quantum dots.

Findings

PV current depends on photon occupation number

Current vanishes when photon and electron-hole pair numbers are equal

Estimated PV current magnitude is around picoamperes

Abstract

We extend the analysis of the effects of electromagnetic (EM) fields on mesoscopic conductors to include the effects of field quantization, motivated by recent experiments on circuit QED. We show that in general there is a photovoltaic (PV) current induced by quantized cavity modes at zero bias across the conductor. This current depends on the average photon occupation number and vanishes identically when it is equal to the average number of thermal electron-hole pairs. We analyze in detail the case of a chaotic quantum dot at temperature T_e in contact with a thermal EM field at temperature T_f, calculating the RMS size of the PV current as a function of the temperature difference, finding an effect ~pA.