Stabilizing quantum simulations of lattice gauge theories by dissipation

TL;DR

This paper proposes a dissipative correction method to actively maintain gauge symmetry in noisy quantum simulations of lattice gauge theories, enhancing the physical accuracy and stability of the results.

Contribution

It introduces a local gauge violation detection and correction scheme that prolongs the validity of quantum simulations within the gauge-invariant sector.

Findings

Gauge violations are effectively corrected, preserving physicality.

The correction scheme extends the duration of reliable simulation results.

Potential application in preparing ground states of many-body systems.

Abstract

Simulations of lattice gauge theories on noisy quantum hardware inherently suffer from violations of the gauge symmetry due to coherent and incoherent errors of the underlying physical system that implements the simulation. These gauge violations cause the simulations to become unphysical requiring the result of the simulation to be discarded. We investigate an active correction scheme that relies on detecting gauge violations locally and subsequently correcting them by dissipatively driving the system back into the physical gauge sector. We show that the correction scheme not only ensures the protection of the gauge symmetry, but it also leads to a longer validity of the simulation results even within the gauge-invariant sector. Finally, we discuss further applications of the scheme such as preparation of the many-body ground state of the simulated system.