Many-body theory of false vacuum decay in quantum spin chains

TL;DR

This paper develops an analytical many-body theory for false vacuum decay in quantum spin chains, matching numerical results and revealing different physical regimes, including those analogous to cosmological decay.

Contribution

It introduces a new bosonic many-body framework for false vacuum decay in quantum spin chains, bridging analytical and numerical approaches.

Findings

The theory matches matrix product state simulations across parameter regimes.

Different decay regimes are identified and characterized.

Cosmological decay scenarios are effectively modeled.

Abstract

In this work we theoretically investigate the false vacuum decay process in a ferromagnetic quantum spin-1/2 chain. We develop a many-body theory describing the nucleation and the coherent dynamics of true-vacuum bubbles that is analytically tractable and agrees with numerical matrix product state calculations in all parameter regimes up to intermediate times. This bosonic theory allows us to identify different regimes in the parameter space and unravel the underlying physical mechanisms. In particular, regimes that closely correspond to the cosmological false vacuum decay picture are highlighted and characterized in terms of observable quantities.