Michael R. Andrews

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Interference between two freely expanding Bose-Einstein condensates has been observed. Two condensates separated by 40 m were created by evap-oratively cooling sodium atoms in a double-well potential created by magnetic and optical forces. High contrast matter-wave interference fringes with a period of 15 m were observed after switching oo the potential and(More)
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Wireless communications are a fundamental part of modern information infrastructure. But wireless bandwidth is costly, prompting a close examination of the data channels available using electromagnetic waves. Classically, radio communications have relied on one channel per frequency, although it is well understood that the two polarization states of planar(More)
The formation of a Bose-Einstein condensate of a dilute atomic gas has been studied in situ with a nondestructive, time-resolved imaging technique. Sodium atoms were evaporatively cooled close to the onset of Bose-Einstein condensation and then suddenly quenched to below the transition temperature. The subsequent equilibration and condensate formation(More)
Bose-Einstein condensation of sodium atoms has been observed in a novel “cloverleaf” trap. This trap combines tight confinement with excellent optical access, using only dc electromagnets. Evaporative cooling in this trap produced condensates of 5 3 106 atoms, a tenfold improvement over previous results. We measured the condensate fraction and the repulsive(More)
s (to be published) Abstract No. 1-M3. [9] W. Petrich, M. H. Anderson, J. R. Ensher, and E. A. Cornell, in Fourteenth International Conference on Atomic Physics, Boulder Colorado, 1994 (Ref. [8]). [10] M. Kasevich (private communication). [11] E. Tiesinga, A. J. Moerdijk, B. J. Verhaar, and H. T. C. Stoof, Phys. Rev. A 46, R1167 (1992). [12] H. F. Hess,(More)
Bose-Einstein condensates of sodium atoms have been confined in an optical dipole trap using a single focused infrared laser beam. This eliminates the restrictions of magnetic traps for further studies of atom lasers and Bose-Einstein condensates. More than 5 3 106 condensed atoms were transferred into the optical trap. Densities of up to 3 3 1015 cm23 of(More)
Sound propagation has been studied in a magnetically trapped dilute Bose-Einstein condensate. Localized excitations were induced by suddenly modifying the trapping potential using the optical dipole force of a focused laser beam. The resulting propagation of sound was observed using a novel technique, rapid sequencing of nondestructive phase-contrast(More)
Collective excitations of a dilute Bose condensate have been observed. These excitations are analogous to phonons in superfluid helium. Bose condensates were created by evaporatively cooling magnetically trapped sodium atoms. Excitations were induced by a modulation of the trapping potential, and detected as shape oscillations in the freely expanding(More)
We have demonstrated an output coupler for Bose condensed atoms in a magnetic trap. Short pulses of rf radiation were used to create Bose condensates in a superposition of trapped and untrapped hyperfine states. The fraction of out-coupled atoms was adjusted between 0% and 100% by varying the amplitude of the rf radiation. This configuration produces output(More)