Dynamically Generated Supersolid-Like Stripe States in Spin-Orbit-Coupled Bose-Einstein Condensates

Supersolids simultaneously exhibit a crystalline structure with long-range order and superfluid properties, two features that typically do not coexist. Systems such as Bose-Einstein condensates (BECs) in cavities, dipolar quantum gases, and spin-orbit-coupled (SOC) BECs offer opportunities to explore supersolid-like quantum states. Here, we experimentally realize an SOC BEC via Raman dressing and study stripe (density modulation) dynamics by exciting its spin-dipole mode using spin-dependent synthetic electric fields. In this mode, two dressed spin components counter-propagate and interfere, leading to stripe dynamics. Our experimental and numerical studies reveal that the increasing damping of the spin-dipole mode with increasing Raman coupling is linked to stripe dynamics and the (im)miscibility behaviors of the dressed spin states. Furthermore, our results show that the stripe spacing is not fixed but evolves over time, indicating compressible stripes. These findings provide insights into the excitations of SOC BECs and their supersolid-like properties.