String breaking is an intriguing phenomenon crucial to the understanding of lattice gauge theories (LGTs), with strong relevance to both condensed matter and high-energy physics (HEP). Recent experiments investigating string breaking in 2+1D (two spatial and one temporal dimensions) LGTs motivate a thorough analysis of its underlying mechanisms. Here, we perform matrix product state (MPS) simulations of string breaking in an experimentally relevant 2+1D Z2 LGT in the presence of two external charges. We provide a detailed description of the system in the confined phase, highlight a number of mechanisms which are responsible for string breaking, and argue that magnetic fluctuations have a stabilizing effect on the strings. Moreover, we show that deep in the confined regime the problem is dual to one-dimensional free fermions hopping on an open chain. Our work elucidates the microscopic processes of string breaking in 2+1D LGTs, and our findings can be probed on current superconducting-qubit quantum computers.
@article{arxiv.2501.17929,
title = {String Breaking in a $2+1$D $\mathbb{Z}_2$ Lattice Gauge Theory},
author = {Umberto Borla and Jesse J. Osborne and Sergej Moroz and Jad C. Halimeh},
journal= {arXiv preprint arXiv:2501.17929},
year = {2025}
}