Quantum computation of mass gap in an asymptotically free theory

TL;DR

This paper introduces a quantum computing method to directly measure the mass gap in relativistic field theories, successfully applying it to a nonlinear sigma-model at different couplings, overcoming traditional precision issues.

Contribution

It presents a novel quantum algorithm for directly extracting the mass gap in asymptotically free theories, validated through hardware and classical simulations.

Findings

Successful quantum hardware calculations at strong coupling

Classical simulations at weak coupling

Demonstration of method's effectiveness in continuum limit

Abstract

In relativistic field theories, the mass spectrum is given by the difference between the energy of the vacuum and the excited states. Near the continuum limit, the cancellation between these two values leads to loss of precision. We propose a method to extract the mass gap directly using quantum computers and apply it to a particular version of the nonlinear $\sigma$-model with the correct continuum limit and perform calculations in quantum hardware (at strong coupling) and simulation in classical computers (at weak coupling).