A Quantum Algorithm for the Linear Response of Nuclei

TL;DR

This paper introduces a quantum algorithm to compute nuclear electromagnetic responses, demonstrating good agreement with experimental data for tin and lead isotopes, and offering a potential quantum advantage in nuclear physics simulations.

Contribution

The paper presents a novel quantum algorithm combining Hamiltonian simulation and the SWAP test to calculate nuclear response functions, advancing quantum computational methods in nuclear physics.

Findings

Quantum algorithm accurately predicts nuclear dipole responses.

Results agree well with experimental data for Sn and Pb isotopes.

Method outperforms traditional linear response theory in certain cases.

Abstract

We present a quantum algorithm to obtain the response of the atomic nucleus to a small external electromagnetic perturbation. The Hamiltonian of the system is presented by a harmonic oscillator, and the linear combination of unitaries (LCU) based method is utilized to simulate the Hamiltonian on the quantum computer. The output of the Hamiltonian simulation is utilized in calculating the dipole response with the SWAP test algorithm. The results of the response function computed using the quantum algorithm are compared with the experimental data and provide a good agreement. We show the results for $^{120}$Sn and $^{208}$Pb to corroborate with the experimental data in Sn and Pb region and also compare the results with those obtained using the conventional linear response theory.