Critical velocity and event horizon in pair-correlated systems with "relativistic" fermionic quasiparticles

TL;DR

This paper investigates the conditions for event horizon formation in pair-correlated systems with relativistic fermionic quasiparticles, revealing that quantum effects prevent horizon formation due to superflow instability at the relativistic critical velocity.

Contribution

It demonstrates that in relativistic fermionic systems, the superflow becomes unstable at the critical velocity, preventing the formation of an event horizon, unlike in conventional superfluids.

Findings

Superflow remains stable in conventional superconductors above Landau threshold.

Quantum vacuum instability occurs at relativistic critical velocity in these systems.

Event horizon cannot form due to superflow collapse caused by quantum effects.

Abstract

The condition for the appearance of event horizon is considered in such pair-correlated systems (superfluids and superconductors) where the fermionic quasiparticles obey the "relativistic" equations. In these systems, the Landau critical velocity of superflow corresponds to the speed of light. In conventional systems, such as s-wave superconductors, the superflow remains stable even above the Landau treshold. We showed that in the "relativistic" systems however the quantum vacuum becomes unstable and the superflow collapses after the "speed of light" is reached, so that horizon cannot appear. Thus an equilibrium dissipationless superfluid flow state and the horizon are incompatible due to quantum effects. This negative result is consistent with the quantum Hawking radiation from the horizon, which would lead to the dissipation of the flow.