Accessing and manipulating dispersive shock waves in a nonlinear and nonlocal Rydberg medium

Dispersive shock waves (DSWs) are fascinating wave phenomena occurring in media when nonlinearity overwhelms dispersion (or diffraction). Creating DSWs with low generation power and realizing their active controls is desirable but remains a longstanding challenge. Here, we propose a scheme to generate weak-light DSWs and realize their manipulations in an atomic gas involving strongly interacting Rydberg states under the condition of electromagnetically induced transparency. We show that for a two-dimensional Rydberg gas, weak nonlocality of optical Kerr nonlinearity can significantly change and induce a singular behavior of the edge speed and hence an instability of the DSWs, which, however, can be suppressed by increasing the degree of the Kerr nonlocality. We also show that in a three-dimensional Rydberg gas, DSWs can be created and propagate stably when the system works in the intermediate nonlocality regime. Different from the DSWs reported before, the DSWs found here have extremely low generation power. Moreover, such DSWs can be actively controlled; in particular, they can be stored and retrieved with high efficiency and fidelity through switching off and on a control laser field. The results reported here are useful not only for unveiling intriguing physics of DSWs but also for finding promising applications of nonlinear and nonlocal Rydberg media.