Saturating interaction in coherently coupled two-component Bose-Einstein condensates

TL;DR

This paper demonstrates how Rabi coupling in two-component Bose-Einstein condensates induces a saturating nonlinear interaction regime, with experimental validation showing the transition controlled by coupling strength.

Contribution

It reveals a novel saturating interaction regime driven by Rabi coupling, bridging low- and high-density behaviors in spinor Bose-Einstein condensates.

Findings

Experimental evidence of saturation in interaction energy

Transition controlled by Rabi coupling strength

Interpolation between different scattering length regimes

Abstract

Rabi-coupled spinor Bose-Einstein condensates, with competing intra-and interspecies interactions, enable independent control of two-and three-body interactions. We show that coupling can also drive the system into a strongly nonlinear regime of saturating interaction. More precisely, the equation of state interpolates between low-and high-density regimes described by two different two-body scattering lengths. Interestingly, the transition can be determined by the strength of the coupling. We experimentally demonstrate this saturation phenomenon by measurements of the interaction energy of a Bose-Einstein condensate as a function of the detuning and of the strength of the Rabi coupling in spin mixtures of potassium 39.