J R. Ensher

Observation of bose-einstein condensation in a dilute atomic vapor.

A Bose-Einstein condensate was produced in a vapor of rubidium-87 atoms that was confined by magnetic fields and evaporatively cooled. The condensate fraction first appeared near a temperature of 170 nanokelvin and a number density of 2.5 x 1012 per cubic centimeter and could be preserved for more than 15 seconds. Three primary signatures of Bose-Einstein condensation were seen. (i) On top of a broad thermal velocity distribution, a narrow peak appeared that was centered at zero velocity. (ii) The fraction of the atoms that were in this low-velocity peak increased abruptly as the sample temperature was lowered. (iii) The peak exhibited a nonthermal, anisotropic velocity distribution expected of the minimum-energy quantum state of the magnetic trap in contrast to the isotropic, thermal velocity distribution observed in the broad uncondensed fraction.

Dynamics of component separation in a binary mixture of Bose-Einstein condensates

We describe the first experiments that study in a controlled way the dynamics of distinguishable and interpenetrating bosonic quantum fluids. We work with a two-component system of Bose-Einstein condensates in the

Dynamical Response of a Bose-Einstein Condensate to a Discontinuous Change in Internal State

|{F\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1,m}_{f}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{-}1〉

Quantitative studies of Bose-Einstein condensation in a dilute atomic vapor

and

Recent experiments with Bose-condensed gases at JILA

|2,1〉

Bose-Einstein condensation: cold new results

spin states of

Collective Excitations of a Bose-Einstein Condensate in a Dilute Gas

{}^{87}\mathrm{Rb}

Stable, Tightly Confining Magnetic Trap for Evaporative Cooling of Neutral Atoms

. The two condensates are created with complete spatial overlap, and in subsequent evolution they undergo complex relative motions that tend to preserve the total density profile. The motions quickly damp out, leaving the condensates in a steady state with a non-negligible (and adjustable) overlap region.

Bose-Einstein Condensation in a Dilute Gas: Measurement of Energy and Ground-State Occupation.

A two-photon transition is used to convert an arbitrary fraction of the 87Rb atoms in a |F=1,m_f=-1> condensate to the |F=2,m_f=1> state. Transferring the entire population imposes a discontinuous change on the condensates mean-field repulsion, which leaves a residual ringing in the condensate width. A calculation based on Gross-Pitaevskii theory agrees well with the observed behavior, and from the comparison we obtain the ratio of the intraspecies scattering lengths for the two states, a_|1,-1> / a_|2,1> = 1.062(12).

REDUCTION OF LIGHT-ASSISTED COLLISIONAL LOSS RATE FROM A LOW-PRESSURE VAPOR-CELL TRAP

We observe Bose-Einstein condensation (BEC) in a dilute atomic gas cooled below 280 nK.87Rb atoms are optically trapped and pre-cooled, loaded into a magnetic trap, and then evaporatively cooled throughthe BEC phase transition. We present results of quantitative studies of condensate fraction, interaction strength, and excitations of the condensate in this system.