Temperature variation of ultraslow light in a cold gas

Stephen G. Benka

Giovanna Morigi, G. S. Agarwal

A model is developed to explain the temperature dependence of the group velocity as observed in the experiments of Hau et al. [Nature (London) 397, 594 (1999)]. The group velocity is quite sensitive to the change in the spatial density. The inhomogeneity in the density and its temperature dependence are primarily responsible for the observed behavior.

Gediminas Juzeliūnas, Patrik Öhberg

José Tito Mendonça, Hugo Terças

Frank Zimmer, Michael Fleischhauer

The advantages of light and matter-wave Sagnac interferometers--large area on one hand and high rotational sensitivity per unit area on the other--can be combined utilizing ultraslow light in cold atomic gases. While a group-velocity reduction alone does not affect the Sagnac phase shift, the associated momentum transfer from light to atoms generates a coherent matter-wave component which gives rise to a substantially enhanced rotational signal. It is shown that matter-wave sensitivity in a large-area interferometer can be achieved if an optically dense vapor at subrecoil temperatures is used. Already a noticeable enhancement of the Sagnac phase shift is possible, however, with far fewer cooling requirements.

Shun-Fang Chen, Ya-Wei Guo, Guo, Qi +4 more

We investigate the formation and propagation of vector vortex solitons (VS) and unipolar soliton (US) in a cold atomic gas with Bessel lattices (BLs). The system we consider is a cold, coherent atomic gas with a tripod or multipod level configuration. Dueing to the giant enhancement of Kerr nonlinearity contributed by electromagnetically induced transparency (EIT), a vector weak vortex soliton can be effectively formed with ultraslow propagating velocity. Furthermore, we demonstrate that the characteristics of 2D VS and US can be controlled and manipulated via adjusting BLs. The results predicted here may be used to design all-optical switching at very low light level.