Fundamentals of Bose—Einstein Condensation

Masahito Ueda

Steven Knoop, Joseph Steven Borbely, Rob van Rooij +1 more

We have studied the decay of a Bose-Einstein condensate (BEC) of metastable helium atoms in an optical dipole trap. In the regime where two- and three-body losses can be neglected we show that the Bose-Einstein condensate and the thermal cloud show fundamentally different decay characteristics. The total number of atoms decays exponentially with time constant $\ensuremath{\tau}$; however, the thermal cloud decays exponentially with time constant $\frac{4}{3}\ensuremath{\tau}$ and the condensate decays much faster, and nonexponentially. We show that this behavior, which should be present for all BECs in thermal equilibrium with a considerable thermal fraction, is due to a transfer of atoms from the condensate to the thermal cloud during its decay.

Claude N. Cohen-Tannoudji

Weiping Zhang, Ewan M. Wright, Han Pu +1 more

The dynamical response of an atomic Bose-Einstein condensate manipulated by an integrated atom-optics device, such as a microtrap or a microfabricated waveguide, is studied. We show that when the miniaturization of the device enforces a sufficiently high condensate density, three-body interactions lead to a spatial modulational instability that results in a fundamental limit on the coherent manipulation of Bose-Einstein condensates.

S. Raghavan, Han Pu, C. K. Law +2 more

Summary form only given. The experimental discovery of Bose-Einstein condensation in dilute alkali atomic gases has revolutionized the field of macroscopic quantum coherence. Further, fundamental issues like symmetry breaking, collapse and revival of macroscopic wavefunctions can perhaps now be tested in an experimentally controllable way. A further step in the control and study of Bose-Einstein condensates (BEC) has been the creation of spinor condensates-BEC in different spin states-through optical confinement and has led to considerable theoretical activity.