Correlation-enhanced Goos-Hänchen shift in Rydberg atomic gases

We present here a theoretical investigation on the Goos-H\"anchen (GH) lateral shift of a probe field as it is reflected or transmitted from a three-layer system with a Rydberg atomic gas sandwiched between two dielectric slabs. Driven by this weak probe field and a strong-coupling field, Rydberg atoms with dipole-dipole interactions are capable of producing a nonlocal Kerr effect whose strength could far exceed the corresponding local Kerr effect at a rather low atomic density. The resultant GH shift is distinct from that observed in an extremely diluted atomic gas with negligible Rydberg-Rydberg interactions and has been examined in two particular cases specified by different coupling frequencies for a fixed probe frequency. In both cases, the nonlocal Kerr effect is found to result in an obvious enhancement of the GH shift and more importantly provide an alternative way for controlling the GH shift by varying the atomic density in an appropriate range. Finally, we present a possible realization of a highly sensitive displacement sensor by exploiting an approximately linear relation between the displacement of one dielectric slab and the GH shift of the probe field.