Many-Body Transition in a Spin-Orbit Coupled Bose-Einstein Condensate

In quantum mechanics, a resonant Rabi oscillation can occur between two degenerate single-particle states when such two states are subject to external perturbations. This phenomenon can be qualitatively different in the interacting regime. In this work, we study a spin-orbit coupled Bose-Einstein condensate with degenerate many-body states and examine the transitions between such states. We find that due to the particle-particle interactions the many-body transitions between such degenerate states are completely different from the physics in single-particle systems. Both the numerical and analytic results will be discussed.