Quantum-Optimal Frequency Estimation of Stochastic AC Fields

Autor:	Dey, Anirban, Mouradian, Sara, Lupo, Cosmo, Huang, Zixin
Rok vydání:	2024
Předmět:	Quantum Physics
Druh dokumentu:	Working Paper
Popis:	Classically, measurement bandwidth limits the achievable frequency resolution of stochastic time-dependent fields. We frame the problem of frequency measurement as the estimation of the noise parameter of a dephasing quantum channel. Using this framework, we find an exact upper bound for estimating frequency centroids and separations. In particular, given two closely separated frequencies with separation $\omega_r$, the quantum Fisher information (QFI) upper bound is approximately $2/\omega_r^2$, inversely proportional to the separation parameter. We show that this is achievable with a superposition of Dicke states, and show that GHZ states improve precision over unentangled states, achieving Heisenberg scaling in the low-bandwidth limit. This work established a robust framework for stochastic AC signal sensing and can be extended to an arbitrary number of frequencies. Comment: 5 pages, 3 figures, and supplemental material, comments are welcome
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2411.19412 Zobrazit plný text záznamu View this record from Arxiv