Giant Kerr nonlinearities and magneto-optical rotations in a Rydberg-atom gas via double electromagnetically induced transparency

We investigate the Kerr and magneto-optical effects for a probe laser field with two orthogonally polarized components, propagating in cold Rydberg atomic gas an inverted-Y-type level configuration via double electromagnetically induced transparency (EIT). Through approach beyond both mean-field ground-state approximations, we make detailed calculations on third-order nonlinear optical susceptibilities show that system possesses giant nonlocal selfand cross-Kerr nonlinearities contributed by Rydberg-Rydberg interaction. The theoretical result of nonlinearity obtained 85Rb is very close to experimental one reported recently. Moreover, demonstrate can acquire large magnetooptical rotation EIT, which may be used design magnetometers high precision. results presented here are promising not only development magneto-optics but also applications precision measurement information processing transmission based gases.