Towards the real-time evolution of gauge-invariant $\mathbb{Z}_2$ and $U(1)$ quantum link models on NISQ Hardware with error-mitigation

TL;DR

This paper demonstrates real-time simulation of gauge-invariant lattice models on NISQ quantum computers, utilizing error mitigation techniques to overcome hardware noise and decoherence, advancing quantum simulation of gauge theories.

Contribution

It introduces methods for simulating gauge-invariant models on NISQ hardware with error mitigation, providing practical strategies for future large-scale quantum lattice gauge theory computations.

Findings

Error mitigation improves measurement accuracy on NISQ devices.

Circuit design impacts the fidelity of gauge-invariant observables.

Hardware-agnostic techniques like circuit folding are effective within hardware limitations.

Abstract

Practical quantum computing holds clear promise in addressing problems not generally tractable with classical simulation techniques, and some key physically interesting applications are those of real-time dynamics in strongly coupled lattice gauge theories. In this article, we benchmark the real-time dynamics of $\mathbb{Z}_2$ and $U(1)$ gauge invariant plaquette models using noisy intermediate scale quantum (NISQ) hardware, specifically the superconducting-qubit-based quantum IBM Q computers. We design quantum circuits for models of increasing complexity and measure physical observables such as the return probability to the initial state, and locally conserved charges. NISQ hardware suffers from significant decoherence and corresponding difficulty to interpret the results. We demonstrate the use of hardware-agnostic error mitigation techniques, such as circuit folding methods implemented via the Mitiq package, and show what they can achieve within the quantum volume restrictions for the hardware. Our study provides insight into the choice of Hamiltonians, construction of circuits, and the utility of error mitigation methods to devise large-scale quantum computation strategies for lattice gauge theories.