Vacuum radiation and frequency-mixing in linear light-matter systems

Niclas Westerberg*, Angus Prain, Daniele Faccio, Patrik Öhberg

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)
31 Downloads (Pure)


Recent progress in photonics has led to a renewed interest in time-varying media that change on timescales comparable to the optical wave oscillation time. However, these studies typically overlook the role of material dispersion that will necessarily imply a delayed temporal response or, stated alternatively, a memory effect. We investigate the influence of the medium memory on a specific effect, i.e. the excitation of quantum vacuum radiation due to the temporal modulation. We construct a framework which reduces the problem to single-particle quantum mechanics, which we then use to study the quantum vacuum radiation. We find that the delayed temporal response changes the vacuum emission properties drastically: frequencies mix, something typically associated with nonlinear processes, despite the system being completely linear. Indeed, this effect is related to the parametric resonances of the light-matter system, and to the parametric driving of the system by frequencies present locally in the drive but not in its spectrum.

Original languageEnglish
Article number065012
JournalJournal of Physics Communications
Issue number6
Publication statusPublished - 26 Jun 2019


  • Dispersive media
  • Light
  • Macroscopic quantum electrodynamics
  • Matter interactions
  • Nonlocal field theories
  • Photon pair production

ASJC Scopus subject areas

  • General Physics and Astronomy


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