Cavity-enhanced detection of spin polarization in a microfabricated atomic vapor cell
Year: 2024
Authors: Ruiz MH., Ma YT., Medhat H., Mazzinghi C., Lucivero VG., Mitchell MW.
Autors Affiliation: Barcelona Inst Sci & Technol, ICFO Inst Ciencies Foton, Castelldefels 08860, Barcelona, Spain; Xi An Jiao Tong Univ, Sch Mech Engn, Xian 710049, Peoples R China; CNR, Ist Nazl Ott, INO, I-50019 Sesto Fiorentino, Italy; Univ Bari Aldo Moro, Dipartimento Interateneo Fis, I-70126 Bari, Italy; ICREA Inst Catalana Recerca & Estudis Avancats, Barcelona 08010, Spain.
Abstract: We demonstrate continuous Pound-Drever-Hall (PDH) nondestructive monitoring of the electron spin polarization of an atomic vapor in a microfabricated vapor cell within an optical resonator. The twochamber silicon and glass cell contains 87Rb and 1.3 amg of N2 buffer gas, and is placed within a planar optical resonator formed by two mirrors with dichroic dielectric coatings to resonantly enhance the coupling to phase-modulated probe light near the D2 line at 780 nm. We describe the theory of signal generation in this system, including the spin-dependent complex refractive index, cavity optical transfer functions, and PDH signal response to spin polarization. We observe cavity transmission and PDH signals across approximately 200 GHz of detuning around the atomic resonance line. By resonant optical pumping on the 795-nm D1 line, we observe spin-dependent cavity line shifts, in good agreement with theory. We use the saturation of the line shift versus optical pumping power to calibrate the number density and efficiency of the optical pumping. In the unresolved sideband regime, we observe quantum noise limited PDH readout of the spin polarization density, with a flat noise floor of 9×109 spins cm-3 Hz-1/2 for frequencies above 700 Hz. We note possible extensions of the technique.
Journal/Review: PHYSICAL REVIEW APPLIED
Volume: 21 (6) Pages from: 64014-1 to: 64014-13
More Information: We thank Jakob Reichel for insights about cavity enhancement; Kostas Mouloudakis, Michael Tayler, and Aleksandra Sierant for laboratory assistance and help-ful discussions; and Jacques Haesler, Sylvain Karlen, and Thomas Overstolz of the Centre Suisse d’Electronique et de Microtechnique SA (CSEM) in Neuchatel (Switzer-land) for providing MEMS vapor cells. This work was supported by European Commission projects MACQSIMAL (820393) , OPMMEG (101099379) , and QUANTIFY (101135931) ; NextGenerationEU (PRTR-C17.I1) ; Spanish Ministry of Science (MCIN) project SAPONARIA (PID2021-123813NB-I00) ; Severo Ochoa Center of Excellence CEX2019-000910-S, Departament de Recerca i Universitats de la Generalitat de Catalunya Grant No. 2021 SGR 01453; Fundacio Privada Cellex; and Fundacio Mir-Puig. M.H.R. acknowledges support from Ayuda PRE2021-098880 financiada por MCIN/AEI/10.13039/501100011033 y por el FSE+. V.G.L. acknowledges financial support from European Union NextGenera-tionEU (PNRR MUR project PE0000023 – NQSTI) and from the Italian Ministry of University and Research (MUR) project Budget MIUR-Dipartimenti di Eccellenza 2023-2027 (Law 232, 11 December 2016) -Quantum Sensing and Modelling for One-Health (QuaSiModO) . H.M. acknowledges financial support from the European Union’s Horizon Europe research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 101081441. Y.M. acknowledges the support from China Scholarship Council (202206280171) .KeyWords: Back-action; Stabilization; Phase; TimesDOI: 10.1103/PhysRevApplied.21.064014Connecting to view paper tab on IsiWeb: Click here