Understanding Hawking radiation from simple models of atomic Bose-Einstein condensates

TL;DR

This paper explores how phonon emission in Bose-Einstein condensates can serve as an analog to Hawking radiation, providing a microscopic quantum explanation without relying on gravitational analogies.

Contribution

It offers a microscopic quantum derivation of Hawking-like phonon emission in Bose-Einstein condensates using a simple analytical model.

Findings

Phonon emission occurs in supersonic flows of Bose-Einstein condensates.

The derivation is based on Bogoliubov theory without gravitational analogies.

A simple 1D model allows for analytical insights into the phenomenon.

Abstract

This chapter is an introduction to the Bogoliubov theory of dilute Bose condensates as applied to the study of the spontaneous emission of phonons in a stationary condensate flowing at supersonic speeds. This emission process is a condensed-matter analog of Hawking radiation from astrophysical black holes but is derived here from a microscopic quantum theory of the condensate without any use of the analogy with gravitational systems. To facilitate physical understanding of the basic concepts, a simple one-dimensional geometry with a stepwise homogenous flow is considered which allows for a fully analytical treatment.