Electromagnetic Field Quantization in Time-Dependent Dielectric Media

TL;DR

This paper develops a Gupta-Bleuler quantization method for electromagnetic fields in time-dependent dielectric media, addressing gauge conditions and unphysical photon contributions, with implications for experimental tests.

Contribution

It introduces a novel quantization scheme for electromagnetic fields in time-varying dielectrics, extending the Gupta-Bleuler approach beyond vacuum conditions.

Findings

Unphysical photon contributions cannot be fully eliminated in this framework.

A generalized Lorentz gauge condition for time-dependent dielectrics is derived.

Potential experimental implications are discussed.

Abstract

We present a Gupta-Bleuler quantization scheme for the electromagnetic field in time-dependent dielectric media. Starting from the Maxwell equations, a generalization of the Lorentz gauge condition adapted to time varying dielectrics is derived. Using this gauge, a Gupta-Bleuler approach to quantize all polarizations of the radiation field and the corresponding constraint condition are introduced. This new approach is different from the quantized electromagnetic field in vacuum in the sense that here the contributions of unphysical photons cannot be thoroughly eliminated, which further lead to a surface charge density. Finally, a discussion of potential experimental tests and possible implication is also made.