PT-symmetric spectral singularity and negative-frequency resonance

S. Pendharker, Y. Guo, F. Khosravi, and Z. Jacob, “PT-symmetric spectral singularity and negative-frequency resonance”, PHYSICAL REVIEW A, vol. 95, no. 3, 2017.
See also: Photonics, Quantum


Vacuum consists of a bath of balanced and symmetric positive- and negative-frequency fluctuations. Media in relative motion or accelerated observers can break this symmetry and preferentially amplify negative-frequency modes as in quantum Cherenkov radiation and Unruh radiation. Here, we show the existence of a universal negative-frequency-momentum mirror symmetry in the relativistic Lorentzian transformation for electromagnetic waves. We show the connection of our discovered symmetry to parity-time (PT) symmetry in moving media and the resulting spectral singularity in vacuum fluctuation-related effects. We prove that this spectral singularity can occur in the case of two metallic plates in relative motion interacting through positive- and negative-frequency plasmonic fluctuations (negative-frequency resonance). Our work paves the way for understanding the role of PT-symmetric spectral singularities in amplifying fluctuations and motivates the search for PT symmetry in novel photonic systems.

Last updated on 05/27/2021