Variations on vacuum decay: the scaling Ising and tricritical Ising field theories

TL;DR

This paper investigates false vacuum decay in scaling Ising and tricritical Ising field theories using numerical methods, confirming some theoretical predictions and exploring complex vacuum structures and decay scenarios.

Contribution

It applies the Truncated Conformal Space Approach to study vacuum decay in Ising models, including novel scenarios with multiple vacua and degeneracy lifting.

Findings

Results align with previous quantum spin chain and field theory studies.

Theoretical predictions match bubble nucleation rate dependence but differ by a model-specific coefficient.

Exploration of complex vacuum structures in tricritical Ising models reveals new decay scenarios.

Abstract

We study the decay of the false vacuum in the scaling Ising and tricritical Ising field theories using the Truncated Conformal Space Approach and compare the numerical results to theoretical predictions in the thin wall limit. In the Ising case, the results are consistent with previous studies on the quantum spin chain and the $\varphi^4$ quantum field theory; in particular we confirm that while the theoretical predictions get the dependence of the bubble nucleation rate on the latent heat right, they are off by a model dependent overall coefficient. The tricritical Ising model allows us on the other hand to examine more exotic vacuum degeneracy structures, such as three vacua or two asymmetric vacua, which leads us to study several novel scenarios of false vacuum decay by lifting the vacuum degeneracy using different perturbations.