arXiv subjects

A. Gorlitz

Publications and source records attributed to A. Gorlitz.

5 recordsLinked to original sources

arXiv2001

Transport of Bose-Einstein Condensates with Optical Tweezers

We have transported gaseous Bose-Einstein condensates over distances up to 44 cm. This was accomplished by trapping the condensate in the focus of an infrared laser and translating the location of the laser focus with controlled acceleration. Condensates of order 1 million atoms were moved into an auxiliary chamber and loaded into a magnetic trap formed by a Z-shaped wire. This transport technique avoids the optical and mechanical access constraints of conventional condensate experiments and creates many new scientific opportunities.

cond-mat.soft↗

arXiv2001

Realization of Bose-Einstein condensates in lower dimensions

Bose-Einstein condensates of sodium atoms have been prepared in optical and magnetic traps in which the energy-level spacing in one or two dimensions exceeds the interaction energy between atoms, realizing condensates of lower dimensionality. The cross-over into two-dimensional and one-dimensional condensates was observed by a change in aspect ratio and saturation of the release energy when the number of trapped atoms was reduced.

cond-mat.soft↗

arXiv2000

Enhancement and suppression of spontaneous emission and light scattering by quantum degeneracy

Quantum degeneracy modifies light scattering and spontaneous emission. For fermions, Pauli blocking leads to a suppression of both processes. In contrast, in a weakly interacting Bose-Einstein condensate, we find spontaneous emission to be enhanced, while light scattering is suppressed. This difference is attributed to many-body effects and quantum interference in a Bose-Einstein condensate.

cond-mat↗

arXiv2000

Amplification of light and atoms in a Bose--Einstein condensate

A Bose-Einstein condensate illuminated by a single off-resonant laser beam (``dressed condensate'') shows a high gain for matter waves and light. We have characterized the optical and atom-optical properties of the dressed condensate by injecting light or atoms, illuminating the key role of long-lived matter wave gratings produced by the condensate at rest and recoiling atoms. The narrow bandwidth for optical gain gave rise to an extremely slow group velocity of an amplified light pulse (1 m/s).

cond-mat.soft↗

arXiv2000

Suppression and enhancement of impurity scattering in a Bose-Einstein condensate

Impurity atoms propagating at variable velocities through a trapped Bose-Einstein condensate were produced using a stimulated Raman transition. The redistribution of momentum by collisions between the impurity atoms and the stationary condensate was observed in a time-of-flight analysis. The collisional cross section was dramatically reduced when the velocity of the impurities was reduced below the speed of sound of the condensate, in agreement with the Landau criterion for superfluidity. For large numbers of impurity atoms, we observed an enhancement of atomic collisions due to bosonic stimulation. This enhancement is analogous to optical superradiance.

cond-mat.soft↗