Nonlinear Self-Trapping Observed in DC Josephson-Junction Experiments

Self-trapping is a phenomenon associated with the nonlinear nature of Bose-Einstein Condensates (BECs). We present a sequence of experiments providing evidence for nonlinear self-trapping in the context of a DC Josephson junction in momentum space. This setting is realized by combining Raman induced spin-orbit coupling with an additional optical lattice. Dynamics are induced by suitable ramp or quench protocols and are monitored using spin- and momentum-resolved imaging. This study explores self-trapping from a macroscopic perspective, where self-trapping has implications for quantum fluctuations, phase transition dynamics, and atomic band structures.