title: Squeezed-light optical magnetometry.
abstract: We demonstrate a light-shot-noise-limited magnetometer based on the Faraday effect in a hot unpolarized ensemble of rubidium atoms. By using off-resonant, polarization-squeezed probe light, we improve the sensitivity of the magnetometer by 3.2 dB. The technique could improve the sensitivity of the most advanced magnetometers and quantum nondemolition measurements of atomic spin ensembles.
authors.affiliation: ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona, Spain.
authors.forename: Florian
authors.initials: F
authors.lastname: Wolfgramm
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cerè
authors.forename: Federica A
authors.initials: FA
authors.lastname: Beduini
authors.forename: Ana
authors.initials: A
authors.lastname: Predojević
authors.forename: Marco
authors.initials: M
authors.lastname: Koschorreck
authors.forename: Morgan W
authors.initials: MW
authors.lastname: Mitchell
mesh_terms: D008280:Magnetics / Q000295:instrumentation* / Q000379:methods; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D055095:Optics and Photonics; D017785:Photons; D012413:Rubidium / Q000737:chemistry*
chemical_list: D012413:Rubidium