Nanomechanical sensor resolving impulsive forces below its zero-point fluctuations Skrabulis, Martynas Sosa, Martin Colombano Zambon, Nicola Carlon Militaru, Andrei Rossi, Massimiliano Frimmer, Martin Novotny, Lukas The sensitivity of a mechanical transducer is ultimately limited by its inherent quantum fluctuations. Here, we use an optically levitated nanoparticle to measure impulsive forces smaller than the particle’s zero-point momentum uncertainty. Our approach relies on reversibly squeezing the levitated particle’s center-of-mass motion to coherently amplify the perturbation. We demonstrate an impulsive-force resolution as small as 6.9  keV/c, a value 0.6 dB below the sensor’s zero-point value. American Physical Society 2026 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_2df8fbb1 https://research-explorer.ista.ac.at/record/22244 Skrabulis M, Sosa MC, Zambon NC, et al. Nanomechanical sensor resolving impulsive forces below its zero-point fluctuations. <i>Physical Review Letters</i>. 2026;136(23). doi:<a href="https://doi.org/10.1103/9wzm-3qyb">10.1103/9wzm-3qyb</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1103/9wzm-3qyb info:eu-repo/semantics/altIdentifier/issn/0031-9007 info:eu-repo/semantics/altIdentifier/e-issn/1079-7114 info:eu-repo/semantics/altIdentifier/arxiv/2601.19392 info:eu-repo/semantics/openAccess