Magnetic Resonance with Squeezed Microwaves

A. Bienfait (1) , P. Campagne-Ibarcq (1) , A. h. H Kiilerich (2) , Xin Zhou (1, 3) , S. Probst (1) , J.  J Pla (4) , T. Schenkel (5) , D. Vion (1) , Daniel Estève (1) , J.  J. l. Morton (6) , K. Moelmer (2) , P. Bertet (1)

1 QUANTRONICS - Quantronics Group
2 Aarhus University [Aarhus]
3 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
4 UNSW - University of New South Wales [Canberra Campus]
5 LBNL - Lawrence Berkeley National Laboratory [Berkeley]
6 UCL - University College of London [London]

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.

Keywords: Magnetism; Quantum Physics; Quantum Information

Domains: Physics [physics]

A. Bienfait, P. Campagne-Ibarcq, A. h. H Kiilerich, Xin Zhou, S. Probst, et al.. Magnetic Resonance with Squeezed Microwaves. Physical Review X, 2017, 7 (4), ⟨10.1103/PhysRevX.7.041011⟩. ⟨hal-01666540⟩