Quantum Computing Calculations for Nuclear Structure and Nuclear Data

TL;DR

This paper explores quantum computing algorithms for nuclear physics, demonstrating realistic deuteron binding calculations and a spectrum-finding method for simplified nuclear models on quantum computers.

Contribution

It introduces a qubit reduction technique for nuclear calculations and a variational quantum eigensolver variant targeting entire spectra.

Findings

Effective qubit reduction for nuclear models.

Successful calculation of deuteron binding energy.

Full spectrum retrieval for simplified shell model.

Abstract

Model calculations of nuclear properties are peformed using quantum computing algorithms on simulated and real quantum computers. The models are a realistic calculation of deuteron binding based on effective field theory, and a simplified two-level version of the nuclear shell model known as the Lipkin-Meshkov-Glick model. A method of reducing the number of qubits needed for practical calculation is presented, the reduction being with respect to the number needed when the standard Jordan-Wigner encoding is used. Its efficacy is shown in the case of the deuteron binding and shell model. A version of the variational quantum eigensolver in which all eigenstates in a spectrum are targetted on an equal basis is shown. The method involves finding the minima of the variance of the Hamiltonian. The method's ability to find the full spectrum of the simplified shell model is presented.