Vacuum fluctuations of the electromagnetic field set a fundamental limit to the sensitivity of a variety of measurements, including magnetic resonance spectroscopy. We report the use of squeezed microwave fields, which are engineered quantum states of light for which fluctuations in one field quadrature are reduced below the vacuum level, to enhance the detection sensitivity of an ensemble of electronic spins at millikelvin temperatures.} By shining a squeezed vacuum state on the input port of a microwave resonator containing the spins, we obtain a 1.2\,dB noise reduction at the spectrometer output compared to the case of a vacuum input. This result constitutes a proof of principle of the application of quantum metrology to magnetic resonance spectroscopy.
@article{arxiv.1610.03329,
title = {Magnetic resonance with squeezed microwaves},
author = {A. Bienfait and P. Campagne-Ibarcq and A. Holm-Kiilerich and X. Zhou and S. Probst and J. J. Pla and T. Schenkel and D. Vion and D. Esteve and J. J. L. Morton and K. Moelmer and P. Bertet},
journal= {arXiv preprint arXiv:1610.03329},
year = {2017}
}
Comments
Main text : 19 pages, 6 figures. Followed by a 18-pages Supplementary Information section, which includes 6 Supplementary Figures