False vacuum decay in an ultracold spin-1 Bose gas

TL;DR

This paper proposes a cold atom system as an analogue for early universe vacuum decay, modeling the process with a spin-1 Bose gas and simulating decay rates with Gross-Pitaevskii methods.

Contribution

It introduces a novel ultracold atom setup to simulate false vacuum decay without time-modulated couplings, bridging cosmology and quantum simulation.

Findings

Decay rates depend on particle density for different isotopes.

Simulation results agree with instanton theoretical predictions.

The system avoids instabilities associated with time-modulated couplings.

Abstract

We propose an ultracold atom analogue of early universe vacuum decay using all three states of a spin-1 Bose gas. We consider a one-dimensional system with both radio frequency and optical Raman coupling between internal states. An advantage of our proposal is the lack of a time-modulated coupling, which can lead to instabilities. Within the elaborate phase structure of the system we identify an effective Klein-Gordon field and use Gross-Pitaevskii simulations within the truncated Wigner approximation to model the decay of its false vacuum. We examine the dependence of the rate of vacuum decay on particle density for $^{7}$Li and $^{41}$K and find reasonable agreement with instanton methods.