Parametric amplification and noise-squeezing in room temperature atomic vapours

Abstract

We report on the use of parametric excitation to coherently manipulate the collective spin state of an atomic vapour at room temperature. Signatures of the parametric excitation are detected in the ground-state spin evolution. These include the excitation spectrum of the atomic coherences, which contains resonances at frequencies characteristic of the parametric process. The amplitudes of the signal quadratures show amplification and attenuation, and their noise distribution is characterized by a strong asymmetry, similarly to those observed in mechanical oscillators. The parametric excitation is produced by periodic modulation of the pumping beam, exploiting a Bell-Bloom-like technique widely used in atomic magnetometry. Notably, we find that the noise-squeezing obtained by this technique enhances the signal-to-noise ratio of the measurements up to a factor of 10, and improves the performance of a Bell-Bloom magnetometer by a factor of 3.

References in corpus (10)

• Optical Magnetometry
• Experimental demonstration of quantum memory for light
• Quantum squeezing of motion in a mechanical resonator
• Mechanical squeezing via parametric amplification and weak measurement
• ${}^3$He-${}^{129}$Xe Comagnetometery using ${}^{87}$Rb Detection and Decoupling
• Generation of a squeezed state of an oscillator by stroboscopic back-action-evading measurement
• Atomic magnetic resonance induced by amplitude-, frequency-, or polarization-modulated light
• Squeezing a thermal mechanical oscillator by stabilized parametric effect on the optical spring
• Parametric Excitation and Squeezing in a Many-Body Spin System
• Linear and non-linear coherent coupling in a Bell-Bloom magnetometer

Cited by in corpus (5)

• Multiparameter quantum sensing and magnetic communications with a hybrid dc and rf optically pumped magnetometer
• Spin dynamic response to a time dependent field
• Spin noise spectroscopy of a noise-squeezed atomic state
• Optimal estimation of conjugate shifts in position and momentum by classically correlated probes and measurements
• Optical protection of alkali-metal atoms from spin relaxation