Spontaneous photon production in time-dependent epsilon-near-zero materials

Prain, A., Vezzoli, S., Westerberg, N. , Roger, T. and Faccio, D. (2017) Spontaneous photon production in time-dependent epsilon-near-zero materials. Physical Review Letters, 118(13), 133904. (doi: 10.1103/PhysRevLett.118.133904) (PMID:28409947)

Abstract

Quantum field theory predicts that a spatially homogeneous but temporally varying medium will excite photon pairs out of the vacuum state. However, this important theoretical prediction lacks experimental verification due to the difficulty in attaining the required nonadiabatic and large amplitude changes in the medium. Recent work has shown that in epsilon-near-zero (ENZ) materials it is possible to optically induce changes of the refractive index of the order of unity, in femtosecond time scales. By studying the quantum field theory of a spatially homogeneous, time-varying ENZ medium, we theoretically predict photon-pair production that is up to several orders of magnitude larger than in non-ENZ time-varying materials. We also find that while in standard materials the emission spectrum depends on the time scale of the perturbation, in ENZ materials the emission is always peaked at the ENZ wavelength. These studies pave the way to technologically feasible observation of photon-pair emission from a time-varying background with implications for quantum field theories beyond condensed matter systems and with potential applications as a new source of entangled light.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Faccio, Professor Daniele and Westerberg, Dr Niclas
• Authors: Prain, A., Vezzoli, S., Westerberg, N., Roger, T., and Faccio, D.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review Letters
• Publisher: American Physical Society
• ISSN: 0031-9007
• ISSN (Online): 1079-7114
• Copyright Holders: Copyright © 2017 The Authors
• First Published: First published in Physical Review Letters 118(13):133904
• Publisher Policy: Reproduced under a Creative Commons License