BEC page at the Kyoto University Quantum Optics Laboratory

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, m_F=+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)

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