Abstract
We demonstrate a new technique for detecting the amplitude of arbitrarily chosen components of radio-frequency waveforms based on stroboscopic backaction evading measurements. We combine quantum nondemolition measurements and stroboscopic probing to detect waveform components with magnetic sensitivity beyond the standard quantum limit. Using an ensemble of cold rubidium atoms, we demonstrate entanglement-enhanced sensing of sinusoidal and linearly chirped waveforms, with 1.0(2) and 0.8(3) dB metrologically relevant noise reduction, respectively. We achieve volume-adjusted sensitivity of , comparable to the best rf magnetometers.
- Received 25 February 2017
DOI:https://doi.org/10.1103/PhysRevLett.119.043603
© 2017 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Quantum Sensing of Magnetic Fields
Published 25 July 2017
A new design for an atomic magnetometer utilizes so-called quantum nondemolition measurements to detect very weak magnetic-field signals.
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