Evaluation of phase shifts for non-relativistic elastic scattering using quantum computers

TL;DR

This paper presents a quantum algorithm for calculating phase shifts in non-relativistic elastic scattering, demonstrating its effectiveness through classical simulations and tests on IBM quantum hardware.

Contribution

It introduces a novel quantum algorithm for phase shift computation in scattering processes, enhanced with a variational approach for improved accuracy and noise resistance.

Findings

Algorithm successfully computes phase shifts on quantum hardware.

Variational improvement enhances accuracy and noise robustness.

Classical simulations validate the algorithm's effectiveness.

Abstract

Simulations of scattering processes are essential in understanding the physics of our universe. Computing relevant scattering quantities from ab initio methods is extremely difficult on classical devices because of the substantial computational resources needed. This work reports the development of an algorithm that makes it possible to obtain phase shifts for generic non-relativistic elastic scattering processes on a quantum computer. This algorithm is based on extracting phase shifts from the direct implementation of the real-time evolution. The algorithm is improved by a variational procedure, making it more accurate and resistant to the quantum noise. The reliability of the algorithm is first demonstrated by means of classical numerical simulations for different potentials, and later tested on existing quantum hardware, specifically on IBM quantum processors.