Manipulation of an elongated internal Josephson junction of bosonic atoms

We report on the experimental characterization of a spatially extended Josephson junction realized with a coherently coupled two-spin-component Bose-Einstein condensate. The cloud is trapped in an elongated potential such that transverse spin excitations are frozen. We extract the nonlinear parameter with three different manipulation protocols. The outcomes are all consistent with a simple local density approximation of the spin hydrodynamics, i.e., of the so-called Bose-Josephson junction equations. We also identify a method to produce states with a well-defined uniform magnetization.

Automated summary

In this study, we experimentally characterized a spatially extended Josephson junction using a coherently coupled two-spin-component Bose-Einstein condensate. The trapped cloud allowed for the freezing of transverse spin excitations. Our results suggest consistency with a simple local density approximation of spin hydrodynamics, the so-called Bose-Josephson junction equations, across different manipulation protocols. Additionally, we identified a method to generate states with a well-defined uniform magnetization.