Dynamical quantum phase transitions of the Schwinger model: real-time dynamics on IBM Quantum

TL;DR

This paper demonstrates the simulation of real-time dynamics and dynamical quantum phase transitions of the Schwinger model on IBM Quantum hardware, highlighting current limitations due to noise and gate errors.

Contribution

It introduces an algorithm for simulating lattice gauge theory dynamics on quantum computers and analyzes the impact of noise on such simulations.

Findings

Successful implementation of Schwinger model dynamics on IBM Quantum

Noise significantly affects the accuracy of the simulation

Comparison with noise models helps understand hardware limitations

Abstract

Simulating real-time dynamics of gauge theories represents a paradigmatic use case to test the hardware capabilities of a quantum computer, since it can involve non-trivial input states preparation, discretized time evolution, long-distance entanglement, and measurement in a noisy environment. We implement an algorithm to simulate the real-time dynamics of a few-qubit system that approximates the Schwinger model in the framework of lattice gauge theories, with specific attention to the occurrence of a dynamical quantum phase transition. Limitations in the simulation capabilities on IBM Quantum are imposed by noise affecting the application of single-qubit and two-qubit gates, which combine in the decomposition of Trotter evolution. The experimental results collected in quantum algorithm runs on IBM Quantum are compared with noise models to characterize the performance in the absence of error mitigation.