First-principle crosstalk dynamics and Hamiltonian learning via Rabi experiments

TL;DR

This paper introduces a method to characterize and learn crosstalk Hamiltonians in multi-qubit quantum systems using simultaneous Rabi experiments, enabling better error mitigation and chip design.

Contribution

The authors develop a novel approach combining simultaneous Rabi experiments with Hamiltonian fitting to accurately model multi-qubit crosstalk dynamics.

Findings

Excellent agreement between predicted and experimental multi-qubit dynamics

Method enables crosstalk characterization without extensive experiments

Potential to reduce coherent errors via digital pulse precompilation

Abstract

Coherent errors constitute a significant barrier to successful large-scale quantum computation. One such error mechanism is crosstalk, which violates spatial locality or the independence of operations. We present a description of crosstalk and learn the underlying parameters by executing novel simultaneous Rabi experiments and fitting the Hamiltonian to the observed data. We use this model to predict three- and four-qubit experiments and observe excellent agreement between our theoretical predictions and experimental results. Our technique enables researchers to study the dynamics of multi-qubit circuits without performing experiments, potentially facilitating the minimization of coherent gate errors via digital pulse precompilation. Additionally, this method provides whole-chip crosstalk characterization, a useful tool for guiding quantum processor design.