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Papers by Jan Arlt

Physical review letters, 2009

We analyze the spinor dynamics of a 87 Rb F = 2 condensate initially prepared in the mF = 0 Zeema... more We analyze the spinor dynamics of a 87 Rb F = 2 condensate initially prepared in the mF = 0 Zeeman sublevel. We show that this dynamics, characterized by the creation of correlated atomic pairs in mF = ±1, presents an intriguing multi-resonant magnetic field dependence induced by the trap inhomogeneity. This dependence is directly linked to the most unstable Bogoliubov spin excitations of the initial mF = 0 condensate, showing that, in general, even a qualitative understanding of the pair creation efficiency in a spinor condensate requires a careful consideration of the confinement.

Physical Review Letters, 1999

We investigate the oscillation of a dilute atomic gas generated by a sudden rotation of the confi... more We investigate the oscillation of a dilute atomic gas generated by a sudden rotation of the confining trap (scissors mode). This oscillation reveals the effects of superfluidity exhibited by a Bose-Einstein condensate. The scissors mode is investigated also in a classical gas above Tc in various collisional regimes. The crucial difference with respect to the superfluid case arises from the occurrence of low frequency components, which are responsible for the rigid value of the moment of inertia. Different experimental procedures to excite the scissors mode are discussed.

Naturwissenschaften, 2002

Bose-Einstein condensation is one of the most curious and fascinating phenomena in physics. It li... more Bose-Einstein condensation is one of the most curious and fascinating phenomena in physics. It lies at the heart of such intriguing processes as superfluidity and superconductivity. However, in most cases, only a small part of the sample is Bose-condensed and strong interactions are present. A weakly interacting, pure Bose-Einstein condensate (BEC) has therefore been called the "holy grail of atomic

Physical Review A, 2003

The coherence properties of phase fluctuating Bose-Einstein condensates are studied both theoreti... more The coherence properties of phase fluctuating Bose-Einstein condensates are studied both theoretically and experimentally. We derive a general expression for the N-particle correlation function of a condensed Bose gas in a highly elongated trapping potential. The second order correlation function is analyzed in detail and an interferometric method to directly measure it is discussed and experimentally implemented. Using a Bragg diffraction interferometer, we measure intensity correlations in the interference pattern generated by two spatially displaced copies of a parent condensate. Our experiment demonstrates how to characterize the second order correlation function of a highly elongated condensate and to measure its phase coherence length.

Physical Review Letters, 2005

We investigate, both experimentally and theoretically, possible routes towards Anderson-like loca... more We investigate, both experimentally and theoretically, possible routes towards Anderson-like localization of Bose-Einstein condensates in disordered potentials. The dependence of this quantum interference effect on the nonlinear interactions and the shape of the disorder potential is investigated. Experiments with an optical lattice and a superimposed disordered potential reveal the lack of Anderson localization. A theoretical analysis shows that this absence is due to the large length scale of the disorder potential as well as its screening by the nonlinear interactions. Further analysis shows that incommensurable superlattices should allow for the observation of the cross-over from the nonlinear screening regime to the Anderson localized case within realistic experimental parameters.