Nuclear two point correlation functions on a quantum-computer

TL;DR

This paper demonstrates the calculation of nuclear two-point correlation functions using current quantum hardware, focusing on a simplified model relevant to nuclear and particle physics, showcasing early quantum computing applications in strongly-correlated systems.

Contribution

It introduces a method to compute nuclear response functions on quantum computers using error mitigation, applied to a simplified Fermi-Hubbard model with real hardware.

Findings

Successful calculation of 2-point correlation functions on quantum hardware

Effective error mitigation protocols improve result accuracy

Potential for applying quantum computing to complex nuclear physics problems

Abstract

The calculation of dynamic response functions is expected to be an early application benefiting from rapidly developing quantum hardware resources. The ability to calculate real-time quantities of strongly-correlated quantum systems is one of the most exciting applications that can easily reach beyond the capabilities of traditional classical hardware. Response functions of fermionic systems at moderate momenta and energies corresponding roughly to the Fermi energy of the system are a potential early application because the relevant operators are nearly local and the energies can be resolved in moderately short real time, reducing the spatial resolution and gate depth required. This is particularly the case in quasielastic electron and neutrino scattering from nuclei, a topic of great interest in the nuclear and particle physics communities and directly related to experiments designed to probe neutrino properties. In this work we use current quantum hardware and error mitigation protocols to calculate response functions for a highly simplified nuclear model through calculations of a 2-point real time correlation function for a modified Fermi-Hubbard model in two dimensions with three distinguishable nucleons on four lattice sites.