Seminario: Quantum sensing and optical magnetometry with hot atoms

Speaker: Dr. Gianvito Lucivero Webpage: https://www.gianvitolucivero.com/

ICFO- The Institute of Photonic Sciences

BIST- Barcelona Institute of Science and Technology

Quantum sensing and metrology are among the four pillars of the European roadmap on quantum technologies. Atomic quantum sensors using alkali-metal vapors, such as magnetometers, clocks, gyroscopes, GHz/THz imagers, and Rydberg-based gas detectors, can be miniaturized [1] and they have already been commercialized.

Optically pumped magnetometers (OPMs), in which an atomic ensemble is optically polarized and its spin-dynamics optically detected, represent a paradigmatic quantum sensing technology, which applies to medical diagnostics, geophysics, navigation, and searches beyond the standard model. For example, OPMs are poised to replace cryogenic superconducting quantum interference devices (SQUIDs) as a more practical, flexible, and cost-effective technology for important biomedical applications like magnetoencephalography (MEG).

In this talk, after a general overview of quantum sensing and optical magnetometry [2], I will present recent results on the miniaturization of atomic sensors by using MEMS cells integrated with mass-producible 3D-printed biplanar coils [3], within the EU project macQsimal [1], and the fabrication of laser-written vapor cells (LWVCs) [4], in collaboration with the CNR/IFN. After that, I will describe state-of-the-art magnetic gradiometers [5, 6] that have reached femtotesla sensitivity up to Earth-scale fields, enabling the first detection of biomagnetism in unshielded environments [7]. Finally, I will discuss the quantum enhancement of high-density atomic sensors by using quantum resources such as squeezed light [8, 9].

[1] https://www.macqsimal.eu/

[2] D. Budker and M. Romalis “Optical Magnetometry”, Nature Physics 3, 227–234 (2007)

[3] M. Tayler et al. “Miniature biplanar coils for alkali-metal-vapor magnetometry”, Phys. Rev. Applied 18, 014036 (2022)

[4] V. G. Lucivero et al. “Laser-written vapor cells for chip-scale atomic sensing and spectroscopy”, 

Optics Express 30, 27149-27163 (2022)

[5] V. G. Lucivero et al. “Femtotesla nearly quantum-noise-limited pulsed gradiometer at Earth-scale fields”

Phys. Rev. Applied 18, L021001 (2022)

[6] V. G. Lucivero et al. “Femtotesla direct magnetic gradiometer using a single multipass cell”,

Phys. Rev. Applied 15, 014004 (2021)

[7] M. E. Limes et al. “Portable magnetometry for detection of biomagnetism in ambient environments”,

Phys. Rev. Applied 14, 011002 (2020)

[8] V. G. Lucivero et al. “Squeezed- light spin noise spectroscopy”, Phys. Rev. A 93, 053802 (2016)

[9] C. Troullinou et al. “Squeezed-light enhancement and backaction evasion in a high-sensitivity optically pumped magnetometer”, Phys. Rev. Lett. 127, 193601 (2021)