Stabilizing lattice gauge theories through simplified local pseudogenerators

The postulate of gauge invariance in nature does not lend itself directly to implementations of lattice gauge theories in modern setups of quantum synthetic matter. Unavoidable gauge-breaking errors in such devices require gauge invariance to be enforced for faithful quantum simulation of gauge-theory physics. This poses major experimental challenges, in large part due to the complexity of the gauge-symmetry generators. Here, we show that gauge invariance can be reliably stabilized by employing simplified local pseudogenerators designed such that within the physical sector they act identically to the actual local generator. Dynamically, they give rise to emergent exact gauge theories up to time scales polynomial and even exponential in the protection strength. This obviates the need for implementing often complex multibody full gauge symmetries, thereby further reducing experimental overhead in physical realizations. We showcase our method in the Z(2) lattice gauge theory, and discuss experimental considerations for its realization in modern ultracold-atom setups.

Automated summary

This article discusses the implementation of gauge invariance in lattice gauge theories in quantum synthetic matter. By using simplified local pseudogenerators, the authors successfully stabilize gauge invariance and reduce experimental overhead and complexity, enabling faithful simulations of exact gauge theories on polynomial and exponential time scales.