Strong coupling of alkali spins to noble-gas spins with hour-long coherence time

Abstract

Nuclear spins of noble gases can maintain coherence for hours at ambient conditions owing to their extraordinary isolation by the enclosing, complete electronic shells [1]. This isolation, however, impedes the ability to manipulate and control them by optical means or by physical coupling to other spin gases [2][3][4]. Here we experimentally achieve strong coherent coupling between noble-gas spins and the optically-accessible spins of alkali-metal vapor. Stochastic spin-exchange collisions, underlying the coupling, accumulate to a coherent periodic exchange of spin excitations between the two gases. We obtain a coupling rate 10 times higher than the decay rate, observe the resultant avoided crossing in the spectral response of the spins, and demonstrate the external control over the coupling by magnetic fields. These results open a route for efficient and rapid interfacing with noble-gas spins for applications in quantum sensing and information [5,6].

New constraints on axion-like dark matter using a Floquet quantum detector

“…Using a linearly polarized optical probe beam, we measure the collective spin of the rubidium along the ˆ x axis via its imprint on the polarization of the probe beam, which rotates after traversing the alkali medium. The polarization rotation is subsequently measured with a set of differential photodiodes in a homodyne configuration (44)(45)(46). While the polarized rubidium spins are initially oriented along the ˆ z axis, they are tilted by an angle…”

NASDUCK: New Constraints on Axion-like Dark Matter from Floquet Quantum Detector

“…Using a linearly polarized optical probe beam, we measure the collective spin of the rubidium along the x-axis via its imprint on the polarization of the probe beam, which rotates after traversing the alkali medium. The polarization rotation is subsequently measured with a set of differential photodiodes in a homodyne configuration [54][55][56]. While the polarized rubidium spins are initially oriented along the ẑ-axis, they are tilted by an angle…”