Cost-effective scalable quantum error mitigation for tiled Ans\"atze

TL;DR

This paper presents a scalable, cost-effective quantum error mitigation method tailored for tiled Ans"atze, significantly reducing noise characterization costs while maintaining accuracy in molecular energy calculations.

Contribution

The authors introduce tiled M0, a novel error mitigation technique exploiting the structure of tiled Ans"atze to reduce quantum processing unit costs exponentially.

Findings

Effective error mitigation for molecular ground states demonstrated on multiple molecules.

Tiled M0 maintains accuracy comparable to M0 in noisy simulations.

Successful experimental validation on quantum hardware shows near-term applicability.

Abstract

We introduce a cost-effective quantum error mitigation technique that builds on the recent Ansatz-based gate and readout error mitigation method (M0). The technique, tiled M0, leverages the unique structure of tiled Ans\"atze (e.g., tUPS, QNP, hardware-efficient circuits) to apply a locality approximation to M0 that results in an exponential reduction in the QPU cost of the noise characterization. We validate the technique for molecular ground state energy calculations with the tUPS Ansatz on LiH, molecular hydrogen, water, butadiene, and benzene ($4-12$ qubits), demonstrating little to no loss in accuracy compared to M0 in noisy simulations. We also show the performance of the technique in quantum experiments, highlighting its potential use in near-term applications.