Bose-Einstein Condensation at the Kyoto University Quantum Optics Laboratory

We have observed Bose-Einstein condensation in 87Rb atoms.


The experiment is performed by a double MOT configuration with a clover-leaf magnetic trap.

Parameters of the experiment are as follows:

  • Loading time of MOT: about 2.5`3 min
  • Number of atoms in MOT: 4 x 109
  • Axial curvature of clover leaf trap: 181 G/cm
  • Radial gradient of clover leaf trap: 87 G/cm2
  • Bias field at the center of the trap: 0.4 G
  • Axial oscillation frequencies: 15 Hz
  • Radial oscillation frequencies: 360 Hz
  • Number of atoms in the magnetic trap: 1.5 x 109
  • Lifetime of the magnetic trap: 90s
  • Temperature in the magnetic trap after compression: about 1 mK
  • Level for magnetic trapping: F=2, mF=+2
  • Evaporation time: about 45 s
  • Number of atoms in the condensate: up to 7 x 105

    BEC
    Time of Flight image of a Bose-Einstein condensate. The spatial distribution of the transmission of a probe beam is plotted along the vertical axis. The central red area corresponds to the condensate,surrounded by the broader blue area of the non-condensated atoms. The flight time is 20ms.


    Multiply charged vortex (winding number 4) by inverting magnetic field of the trap.

    BEC

    Parameters of the experiment are as follows:
  • Bias field at the center of the trap (Before reversing magnetic field):0.4G
  • Reversing time: 2.2ms
  • Bias field at the center of the trap (After reversing magnetic field): -0.2G


    present member

  • Yoshiro Takahashi(staff)
  • Masayuki Okano(Doctor 1st)
    previous member
  • Kentaro Kasa
  • Mitsutaka Kumakura(in Fukui University)
  • Tsutomu Yabuzaki(in Osaka Electronic-Communication University)
  • Takashi Hirotani
  • Yukari Shirahata
  • Nobuhiko Shima
  • Noriyuki Kimura
  • Tsuyoshi Kuwamoto(in Gakushuin University)
  • Kenji Toyoda(in Osaka University)

    If you have any comments, please mail to:

  • Y. Takahashi (yitk@yagura.scphys.kyoto-u.ac.jp)

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