Variational Quantum Computation of Molecular Linear Response Properties on a Superconducting Quantum Processor

TL;DR

This paper presents a practical variational quantum algorithm for simulating molecular response properties, successfully demonstrating its application on a superconducting quantum processor, thus advancing near-term quantum chemistry simulations.

Contribution

The paper introduces the first variational quantum response algorithm capable of computing molecular linear response properties on noisy intermediate-scale quantum devices.

Findings

First simulation of molecular response properties on a quantum processor

Demonstrates feasibility of calculating dynamical properties with near-term hardware

Shows potential of error mitigation techniques in quantum simulations

Abstract

Simulating response properties of molecules is crucial for interpreting experimental spectroscopies and accelerating materials design. However, it remains a long-standing computational challenge for electronic structure methods on classical computers. While quantum computers hold the promise to solve this problem more efficiently in the long run, existing quantum algorithms requiring deep quantum circuits are infeasible for near-term noisy quantum processors. Here, we introduce a pragmatic variational quantum response (VQR) algorithm for response properties, which circumvents the need for deep quantum circuits. Using this algorithm, we report the first simulation of linear response properties of molecules including dynamic polarizabilities and absorption spectra on a superconducting quantum processor. Our results indicate that a large class of important dynamical properties such as Green's functions are within the reach of near-term quantum hardware using this algorithm in combination with suitable error mitigation techniques.