Relationship between Hawking radiation from black holes and spontaneous excitation of atoms

TL;DR

This paper demonstrates that a two-level atom near a black hole spontaneously excites due to Hawking radiation, linking quantum field effects in curved spacetime with atomic excitation phenomena.

Contribution

It establishes a direct connection between Hawking radiation and atomic spontaneous excitation in a black hole background using a formalism separating vacuum fluctuations and radiation reaction.

Findings

Atoms spontaneously excite in black hole backgrounds at Hawking temperature

Hawking radiation causes atomic excitation in vacuum outside black holes

The study unifies phenomena of Hawking radiation and atomic excitation

Abstract

Using the formalism that separates the contributions of vacuum fluctuations and radiation reaction to the rate of change of the mean atomic energy, we show that a two-level atom in interaction with a quantum massless scalar field both in the Hartle-Hawking and Unruh vacuum in a 1+1 dimensional black hole background spontaneously excites as if there is thermal radiation at the Hawking temperature emanating from the black hole. Our calculation, therefore, ties the existence of Hawking radiation to the spontaneous excitation of a two-level atom placed in vacuum in the exterior of a black hole and shows pleasing consistence of two different physical phenomena, the Hawking radiation and the spontaneous excitation of atoms, which are quite prominent in their own right.