Development of Zero-Noise Extrapolated Projection Based Quantum Algorithm for Accurate Evaluation of Molecular Energetics in Noisy Quantum Devices

TL;DR

This paper introduces ZNE-PQE, an enhanced quantum algorithm that combines zero-noise extrapolation with the projective quantum eigensolver to improve the accuracy of molecular energy calculations on noisy quantum devices.

Contribution

It develops a novel framework integrating ZNE with PQE, providing a systematic way to reduce noise and improve energy convergence in quantum molecular simulations.

Findings

ZNE-PQE shows improved energy accuracy over conventional PQE.

The method effectively suppresses noise-induced errors in quantum computations.

Analysis of the residue norm landscape explains the enhanced performance.

Abstract

The recently developed Projective Quantum Eigensolver (PQE) offers an elegant procedure to evaluate the ground state energies of molecular systems on quantum computers. However, the noise in available quantum hardware can result in significant errors in computed outcomes, limiting the realization of quantum advantage. Although PQE comes equipped with some degree of inherent noise resilience, any practical implementation with apposite accuracy would require additional routines to suppress the errors further. In this work, we propose a way to enhance the efficiency of PQE by developing an optimal framework for introducing Zero Noise Extrapolation (ZNE) in the nonlinear iterative procedure that outlines the PQE; leading to the formulation of ZNE-PQE. For this method, we perform a detailed analysis of how various components involved in it affect the accuracy and efficiency of the reciprocated energy convergence trajectory. Moreover, we investigate the reasons behind the improvements observed in ZNE-PQE over conventional PQE by performing a comparative analysis of their residue norm landscape. This approach is expected to facilitate practical applications of quantum computing in fields related to molecular sciences, where it is essential to determine molecular energies accurately.