Hawking radiation in a two-component Bose-Einstein condensate

TL;DR

This paper models Hawking radiation in a one-dimensional two-component Bose-Einstein condensate, showing that only polarization quasiparticles are emitted as Hawking radiation, with implications for experiments in atomic condensates and microcavities.

Contribution

It introduces a simple model of an event horizon affecting only polarization quasiparticles in a two-component BEC, analyzing the resulting Hawking radiation signals.

Findings

Hawking radiation manifests only in polarization waves.

Explicit computation confirms polarization-only emission.

Results have experimental implications for atomic BECs and microcavities.

Abstract

We consider a simple realization of an event horizon in the flow of a one-dimensional two-component Bose-Einstein condensate. Such a condensate has two types of quasiparticles; In the system we study, one corresponds to density fluctuations and the other to polarization fluctuations. We treat the case where a horizon occurs only for one type of quasiparticles (the polarization ones). We study the one- and two-body signal associated to the analog of spontaneous Hawking radiation and demonstrate by explicit computation that it consists only in the emission of polarization waves. We discuss the experimental consequences of the present results in the domain of atomic Bose-Einstein condensates and also for the physics of exciton-polaritons in semiconductor microcavities.