Certified Fidelity Susceptibility from Classical Shadows

Abstract:Fidelity susceptibility is a useful probe of quantum phase transitions and quantum metrology, but its direct evaluation on a quantum device is challenging. By integrating Krylov-subspace methods with a resolvent-based reformulation, we present a method for certifying fidelity susceptibility using randomized single-copy measurements across repeated ground-state preparations. The resulting approximations form monotone lower bounds to the exact fidelity susceptibility and converge geometrically. We also present applications to metrology and linear static susceptibilities.

arXiv:2608.24732 [quant-ph]

(or arXiv:2608.24732v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2608.24732 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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