Sensitive detection of magnetic fields has applications ranging from brain imaging to space exploration, and many technogologies have been developed for these many applications. Until now, all have been limited in sensitivity by the so-called “energy resolution limit,” which constrains the combined spatial, temporal, and field resolution of the sensor. The in-practice limit was suspiciously close to hbar, the fundamental constant that defines the scale of the quantum world. In 2020 we analyzed the energy resolution limit (Mitchell et al. Rev. Mod. Phys. 2020), and concluded that exotic sensor types could beat this “limit.” In 2022 we employed a spinor Bose-Einstein condensate, to do just that, beating all previous sensors by almost two orders of magnitude, and more importantly showing that quantum physics does not place a hard limit on the sensitivity of field measurements (Palacios et al. PNAS 2022).
Morgan W. Mitchell
Institut de Ciències Fotòniques (ICFO)
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References:
– Palacios Alvarez S, Gomez P, Coop S, Zamora-Zamora R, Mazzinghi C & Mitchell MW 2022, ‘ Single-domain Bose condensate magnetometer achieves energy resolution per bandwidth below h’, Proceedings Of The National Academy Of Sciences Of The United States Of America, 119, 6, e2115339119.
– Mitchell MW & Palacios Alvarez S 2020, ‘Colloquium: Quantum limits to the energy resolution of magnetic field sensors’, Reviews of Modern Physics, 92, 2, 021001.
