Molecular electric dipole moments: from light to heavy molecules using a relativistic VQE algorithm

TL;DR

This paper extends the Variational Quantum Eigensolver (VQE) algorithm to relativistic regimes to accurately compute ground state energies and electric dipole moments of diatomic molecules, from light to heavy elements.

Contribution

It introduces a relativistic VQE approach for molecular simulations, enabling the study of heavy molecules with relativistic effects included.

Findings

Successful quantum simulations of diatomic molecules from BeH to RaH.

Assessment of correlation trends and precision within a 12-qubit active space.

Validation of the relativistic VQE method for heavy molecule properties.

Abstract

The quantum-classical hybrid Variational Quantum Eigensolver (VQE) algorithm is recognized to be the most suitable approach to obtain ground state energies of quantum many-body systems in the noisy intermediate scale quantum era. In this work, we extend the VQE algorithm to the relativistic regime and carry out quantum simulations to obtain ground state energies as well as molecular permanent electric dipole moments of single-valence diatomic molecules, beginning with the light BeH molecule and all the way to the heavy radioactive RaH molecule. We study the correlation trends in these systems as well as assess the precision in our results within our active space of 12 qubits.