Quantum Optics Seminar by Dayou Yang

New Opportunities for Sensing via Continuous Measurement

The continuous monitoring of driven-dissipative quantum optical systems provides key strategies for the implementation of quantum metrology, with prominent examples ranging from the gravitational wave detectors to the emergent driven-dissipative many-body sensors. Fundamental questions about the ultimate performance of such a class of sensors remain open—for example, how to perform the optimal continuous measurement to unlock their ultimate precision; how to effectively enhance their precision scaling towards the Heisenberg limit? In this talk I will present our recent theoretical efforts towards answering these questions. In the first part I will present a universal backaction evasion strategy [1] for retrieving the full quantum Fisher information from the nonclassical, temporally correlated fields emitted by generic open quantum sensors, thereby to achieve their fundamental precision limit. In the second part I will introduce dissipative criticality as a resource for nonclassical precision scaling for continuously monitored sensors [2], by establishing universal scaling laws of the quantum Fisher information in terms of critical exponents of generic dissipative critical points. Finally, if time permits, I will briefly touch on our effects to determine the precision of generic continuous sensors subjected to experimental noise.

1] Yang, Huelga & Plenio, PRX 13, 031012 (2023)

[2] Ilias, Yang, Huelga & Plenio, PRX QUANTUM 3, 010354 (2022)