Work

Memory-assisted squeezed light velocimetry under realistic loss and incoherent noise

Year: 2026

Type: article

Abstract: We propose a velocity sensor based on a two-memory Mach–Zehnder interferometer fed by a coherent probe and squeezed vacuum, read out by balanced homodyne detection. One memory is taken as a stationary reference, while the second memory moves during storage, so that its velocity is mapped onto a differential interferometric phase at readout. The two memories are otherwise assumed identical and are described by a Gaussian write–store–read lifetime together with the associated unconditional noise floor. Using the classical Fisher information, we derive the velocity sensitivity, the transmission threshold required for a target quantum gain, and the optimum storage time. The squeezed scheme improves on equal-resource coherent homodyne within an operating window set mainly by total transmission and phase stability. For representative near-term parameters, unconditional memory noise floors up to about 10−1 photons per trial do not by themselves remove the advantage; after optimization, the improvement remains at the few-percent level and is limited chiefly by loss.

Source: AVS Quantum Science

DOI: 10.1116/5.0345557

Authors: Mustafa Gündoğan, Arash Ahmadi, Markus Krutzik

Institutions: Humboldt-Universität zu Berlin, Ferdinand-Braun-Institut

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: hybrid

Funders: Deutsche Forschungsgemeinschaft, Deutsches Zentrum für Luft- und Raumfahrt, Einstein Stiftung Berlin

Awards: G5259393892, Kompakter Geschwindigkeitssensor basierend auf FresnelFizeau Effekt, G9000357694