Internal Josephson effect in trapped double condensates

Abstract

The two-component Bose-Einstein condensate exhibits oscillations in the individual particle number when the two species are coupled by a Josephson coupling. We present the results of numerical calculations based on coupled Gross-Pitaevskii equations, and compare the results with an approximate analytic theory. The small amplitude limit reproduces the conventional results, but the large signal regime offers some features characteristic of the trapped systems.