Quantum vacuum radiation spectra from a semiconductor microcavity with a time-modulated vacuum Rabi frequency

TL;DR

This paper presents a comprehensive quantum theory for vacuum radiation in a semiconductor microcavity with time-varying vacuum Rabi frequency, revealing significant photon pair production and potential parametric oscillation.

Contribution

It introduces a general theoretical framework including losses for vacuum radiation from modulated quantum wells in microcavities, highlighting new spectral features and photon generation mechanisms.

Findings

Photon pairs exceed black-body radiation in IR range

Significant photon production with realistic parameters

Possible parametric oscillation at large modulation amplitudes

Abstract

We develop a general theory of the quantum vacuum radiation generated by an arbitrary time-modulation of the vacuum Rabi frequency for an intersubband transition of a doped quantum well system embedded in a semiconductor planar microcavity. Both non-radiative and radiative losses are included within an input-output quantum Langevin framework. The intensity and the main spectral signatures of the extra-cavity emission are characterized as a function of the amplitude and the frequency of the vacuum modulation. A significant amount of photon pairs, which can largely exceed the black-body radiation in the mid and far infrared, is shown to be produced with realistic parameters. For a large amplitude resonant modulation, a parametric oscillation regime can be also achieved.