Reflectance of a quantum mirror

TL;DR

This paper investigates how the quantum nature of a mirror affects photon reflectance, revealing that the mirror's wavefunction spread influences reflectance and limits entanglement with a photon.

Contribution

It introduces a quantum mechanical model of mirror reflectance and demonstrates the fundamental limit on photon-mirror entanglement due to wavefunction spread.

Findings

Reflectance depends on the mirror's wavefunction spread

Single reflection limits photon-mirror entanglement

Quantum treatment alters classical reflectance assumptions

Abstract

The problem of the reflectance of a photon by a metallic mirror whose position is treated quantum mechanically is considered. The interaction between the metallic surface and the light is treated classically. It is shown that the reflectance depends on the spread of the wavefunction describing the reflecting surface along its normal. Considering this decrease on the mirror reflectance, it is shown by first principles that it is impossible to achieve a highly entangled state between a photon and a mirror when the photon can be reflected only once.