Robust Interaction-Enhanced Sensing via Antisymmetric Rabi Spectroscopy

Abstract: Atomic spectroscopy, an essential tool for frequency estimation, is widely used in quantum sensing. Atom-atom interaction can be used to generate entanglement for achieving quantum enhanced sensing. However, atom-atom interaction always induces collision shift, which brings systematic error in determining the resonance frequency. Contradiction between utilizing atom-atom interaction and suppressing collision shift generally exists in atomic spectroscopy. Here, we propose an antisymmetric Rabi spectroscopy protocol without collision shift in the presence of atom-atom interactions. We analytically find that the antisymmetric point can be used for determining the resonance frequency. For small Rabi frequency, our antisymmetric Rabi spectroscopy with slight atom-atom interaction can provide better measurement precision than the conventional Rabi spectroscopy. With stronger atom-atom interaction and Rabi frequency, the spectrum resolution can be dramatically improved and the measurement precision may even beat the standard quantum limit. Moreover, unlike the quantum-enhanced Ramsey interferometry via spin squeezing, our scheme is robust against detection noises. Our antisymmetric Rabi spectroscopy protocol has promising applications in various practical quantum sensors such as atomic clocks and atomic magnetometers.