Parametric amplification and noise squeezing in room temperature atomic vapors

Research output: Contribution to journalArticlepeer-review

Authors

External organisations

  • National Physical Laboratory
  • University of Siena

Abstract

We report on the use of parametric excitation to coherently manipulate the collective spin state of an atomic vapor 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, similar 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.

Details

Original languageEnglish
Article number033601
Number of pages5
JournalPhysical Review Letters
Volume123
Issue number3
Publication statusPublished - 17 Jul 2019