Hawking radiation from acoustic black holes in hydrodynamic flow of electrons

TL;DR

This paper explores the theoretical possibility of Hawking radiation occurring in acoustic black holes formed by hydrodynamic electron flow, predicting observable current fluctuations and correlations as evidence.

Contribution

It extends the concept of acoustic black holes and Hawking radiation to the hydrodynamic flow of electrons, proposing observable signatures in electronic systems.

Findings

Hawking radiation can manifest as current fluctuations in electron flows.

Correlations between current fluctuations on both sides of the acoustic horizon are predicted.

Theoretical framework connects acoustic black hole physics with electronic hydrodynamics.

Abstract

Acoustic black holes are formed when a fluid flowing with subsonic velocities, accelerates and becomes supersonic. When the flow is directed from the subsonic to supersonic region, the surface on which the normal component of fluid velocity equals the local speed of sound acts as an acoustic horizon. This is because no acoustic perturbation from the supersonic region can cross it to reach the subsonic part of the fluid. One can show that if the fluid velocity is locally irrotational, the field equations for acoustic perturbations of the velocity potential are identical to that of a massless scalar field propagating in a black hole background. One, therefore, expects Hawking radiation in the form of a thermal spectrum of phonons. There have been numerous investigations of this possibility, theoretically, as well as experimentally, in systems ranging from cold atom systems to quark-gluon plasma formed in relativistic heavy-ion collisions. Here we investigate this possibility in the hydrodynamic flow of electrons. Resulting Hawking radiation in this case should be observable in terms of current fluctuations. Further, current fluctuations on both sides of the acoustic horizon should show correlations expected for pairs of Hawking particles.