Simple broadband signal detection at the fundamental limit

Anthony M. Polloreno; Graeme Smith

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arXiv · 2601.19816

Simple broadband signal detection at the fundamental limit

Anthony M. Polloreno·Graeme Smith

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Abstract

Broadband detection of a weak oscillatory field with unknown carrier frequency underlies magnetometry, axion searches and gravitational-wave sensing. We show that the Grover-like integration-time lower bound for this task is a geometric corollary of an upper bound on the integrated quantum Fisher information and present an all-analog protocol with near-optimal scaling.

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Anthony M. Polloreno, Graeme Smith. 2026-01-27. Simple broadband signal detection at the fundamental limit. https://arxiv.org/abs/2601.19816

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