Quantum computing for extracting nuclear resonances

TL;DR

This paper introduces a quantum computing approach combined with the complex scaling method to accurately compute nuclear resonances, overcoming non-Hermiticity challenges and optimizing measurement techniques.

Contribution

It presents a novel method to embed non-Hermitian operators into unitary operators and improves measurement efficiency for quantum simulations of nuclear resonances.

Findings

Quantum approach yields eigenenergies consistent with classical methods.

Optimized quantum circuit enhances measurement accuracy for complex eigenvalues.

Method applicable to nuclear systems like the alpha-alpha resonance.

Abstract

Quantum computing has been increasingly applied in nuclear physics. In this work, we combine quantum computing with the complex scaling method to address the resonance problem. Due to the non-Hermiticity introduced by complex scaling, standard quantum computing cannot solve for complex eigenvalues directly. Therefore, it is necessary to embed the non-Hermitian operator into a larger dimensional unitary operator. Additionally, for the case of two basis vectors, we improve the traditional direct measurement method and optimize the quantum circuit. Ultimately, using the $\alpha+\alpha$ system as an example, we obtain the complex eigenenergies from the quantum computer that are consistent with those obtained from direct Hamiltonian diagonalization.