When coherent light interacts with coherent atoms-optical properties of Bose-Einstein condensates

Wolfgang Ketterle

Summary form only given. Bose-Einstein condensed atomic gases are a new class of quantum fluids with many novel properties. We have studied collective modes and dissipation by perturbing the condensate with focused laser beams. The scattering of photons imparts momentum to the condensate and creates excitations. Consequently, the coherence and collective behavior of the condensate can strongly affect optical properties. We used light scattering to demonstrate that the coherence length of a condensate is equal to its physical size, and obtained dramatic evidence for the presence of correlated momentum excitations in the many-body condensate wavefunction. At higher laser intensity, a new form of superradiance was found which provided a gain mechanism for the generation of directed beams of atoms and light. This process amplified matter waves in a phase coherent way.

Kristian Helmerson

S. Inouye, Tilman Pfau, Robert Loew +7 more

Ming Li

The Hamiltonian operator of a system of V-type three-level atomic Bose-Einstein condensation interacting with two-mode squeezed coherent light field is analyzed in terms of the lattice-liquid model. It is indicated that the contribution of the interaction between atoms to the Hamiltonian in the literature is irrational,so the Hamiltonian operator is improved and the squeezing properties of atomic laser coupled output from the system of V-type three-level atomic Bose-Einstein condensation interacting with two-mode squeezed coherent light field are studied. The results show that the interaction intensity of light-atoms in the Bose-Eimtein condenation has evident influence on the fluctuations of two quadrature components of the atomic laser.

Ren-Fei Zheng, Qi-Hui Jiang, Lu Zhou +1 more

We consider the model of a weakly driven optical cavity containing two clouds of atomic Bose–Einstein condensates (BECs). Nonclassical photon correlations and correlations between the two atomic BECs are investigated under different cavity conditions including strong atom-field coupling and bad cavity regime. We show that the nonlinear interatom collisional interactions in BEC leads to a significant loss of cavity light coherence. Various types of nonclassical properties are investigated such as sub-Poissonian statistics, antibunching and entanglement. We show that the entanglement can be generated between BECs and the cavity field. The time evolution of entanglement is also numerically studied.

H. L. Haroutyunyan