Practical techniques for high-precision measurements on near-term quantum hardware and applications in molecular energy estimation

TL;DR

This paper presents practical techniques to improve measurement precision on near-term quantum hardware, significantly reducing errors in molecular energy estimation crucial for quantum chemistry applications.

Contribution

It introduces combined measurement strategies including biased measurements, repeated tomography, and scheduling to mitigate noise and overheads in quantum measurements.

Findings

Reduced measurement errors from 1-5% to 0.16%.

Demonstrated techniques on IBM quantum hardware for molecular energy estimation.

Enhanced reliability of quantum computations for chemistry applications.

Abstract

Achieving high-precision measurements on near-term quantum devices is critical for advancing quantum computing applications. Quantum computers suffer from high readout errors, making quantum simulations with high accuracy requirements particularly challenging. This paper implements practical techniques to reach accuracies essential for quantum chemistry by addressing key overheads and noise sources. Specifically, we leverage locally biased random measurements for reducing shot overhead, repeated settings with parallel quantum detector tomography for reducing circuit overhead and mitigating readout errors, and blended scheduling for mitigating time-dependent noise. We demonstrate these techniques via molecular energy estimation of the BODIPY molecule on a Hartree-Fock state on an IBM Eagle r3, obtaining a reduction in measurement errors by an order of magnitude from 1-5% to 0.16%. These strategies pave the way for more reliable quantum computations, particularly for applications requiring precise molecular energy calculations.