Robust optimal control of interacting multi-qubit systems for quantum sensing

TL;DR

This paper introduces a robust optimal control method to reliably generate entangled multi-qubit states in quantum systems despite uncertainties, enhancing quantum sensing precision.

Contribution

It presents a novel control technique that maintains high fidelity in multi-qubit systems under parameter uncertainties, advancing quantum state preparation.

Findings

Effective generation of GHZ states on a star graph of transmons.

Improved quantum sensing precision approaching the Heisenberg limit.

Robust control maintains performance despite experimental uncertainties.

Abstract

Realising high fidelity entangled states in controlled quantum many-body systems is challenging due to experimental uncertainty in a large number of physical quantities. We develop a robust optimal control method for achieving this goal in finite-size multi-qubit systems despite significant uncertainty in multiple parameters. We demonstrate its effectiveness in the generation of the Greenberger-Horne-Zeilinger state on a star graph of capacitively coupled transmons, and discuss its crucial role for achieving the Heisenberg limit of precision in quantum sensing.