Journal ArticleDOI
Observation of Bose-Einstein Condensation in a Dilute Atomic Vapor
TLDR
A Bose-Einstein condensate was produced in a vapor of rubidium-87 atoms that was confined by magnetic fields and evaporatively cooled and 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.Abstract:
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 10 12 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.read more
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Book
Do We Really Understand Quantum Mechanics
TL;DR: In this paper, the authors present a general discussion of several aspects of our present understanding of quantum mechanics, focusing on the very special correlations that this theory makes possible: they are forbidden by very general arguments based on realism and local causality.
Journal ArticleDOI
Computing Ground States of Spin-1 Bose-Einstein Condensates by the Normalized Gradient Flow
Weizhu Bao,Fong Yin Lim +1 more
TL;DR: The key idea is to find a third projection or normalization condition based on the relation between the chemical potentials so that the three projection parameters used in the projection step of the normalized gradient flow are uniquely determined by this condition as well as the other two physical conditions given by the conservation of total mass and total magnetization.
Journal ArticleDOI
Direct energy cascade in two-dimensional compressible quantum turbulence
TL;DR: In this article, the authors numerically studied two-dimensional quantum turbulence with a Gross-Pitaevskii model, and showed that a direct energy cascade with a Kolmogorov-Obukhov energy spectrum E(k)-proportional-to-k{sup -5/3} is observed.
Journal ArticleDOI
Dynamics of collapse of a confined Bose gas
TL;DR: In this paper, the authors analyzed the temporal evolution of the mean square radius I = ∫ r 2 | ψ | 2 d V of a dilute Bose gas in a harmonic magnetic trap and formulated sufficient conditions for the collapse of the system.
Journal ArticleDOI
Cooling and Mass-Analysis of Molecules Using Laser-Cooled Atoms
Takashi Baba,Izumi Waki +1 more
TL;DR: In this article, a combination of sympathetic cooling and in situ mass spectroscopy is used to detect sympathetically-cooled molecular ions non-destructively in a radio-frequency quadrupole (RFQ).
References
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Proceedings Article
Bose-Einstein condensation in a gas of sodium atoms
TL;DR: The striking signature of Bose condensation was the sudden appearance of a bimodal velocity distribution below the critical temperature of ~2µK.
Journal ArticleDOI
Trapping of neutral sodium atoms with radiation pressure
TL;DR: The confinement and cooling of an optically dense cloud of neutral sodium atoms by radiation pressure was reported, provided by three retroreflected laser beams propagating along orthogonal axes, with a weak magnetic field used to distinguish between the beams.
Journal ArticleDOI
Plancks Gesetz und Lichtquantenhypothese
TL;DR: In this article, the authors describe how the Phasenraum eines Lichtquants in bezug auf ein gegebenes Volumen wird in „Zellen“ von der Grose h3 aufgeteilt, i.e., the Zahl der moglichen Verteilungen der Lichtquanten einer makroskopisch definierten Strahlung unter diese Zellen liefert die Entropie.
Journal ArticleDOI
Observation of atoms laser cooled below the Doppler limit
Paul D. Lett,Richard N. Watts,Christoph I Westbrook,William D. Phillips,Phillip L. Gould,Harold Metcalf +5 more
TL;DR: This "Doppler cooling limit" results from the minimization of the detuning-dependent temperature at low laser power1.
Journal ArticleDOI
Output Coupler for Bose-Einstein Condensed Atoms
TL;DR: In this paper, an output coupler for Bose condensed atoms in a magnetic trap was demonstrated, where short pulses of rf radiation were used to create Bose condensates in a superposition of trapped and untrapped hyperfine states.