Private Correlations Certify Sensing Capability

Abstract:We show that private correlations in a bipartite quantum state constitute a metrological resource for distributed sensing assisted by a possibly noisy channel from one party to the other. We begin with an example with distillable secret key but poor locally accessible sensing performance and show that an assisting channel substantially improves its performance. We then show that any shared state yielding positive private information can serve as a sensing resource after appropriate local coherent processing, and derive a quantitative lower bound on the locally accessible sensing capability after assistance. We further show that classical correlations alone provide no analogous guarantee. Finally, in a channel formulation, we show that a channel with positive private information allows nonzero locally accessible sensitivity when paired with a suitable assisting channel.

Quantum Physics (quant-ph); Optics (physics.optics)

arXiv:2608.10377 [quant-ph]

(or arXiv:2608.10377v2 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2608.10377 Focus to learn more arXiv-issued DOI via DataCite

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