BEC (down) under a chip
First observation:
BEC! -
report: Feb. 20, 2004
Group:
Vale/Rubinsztein-Dunlop
Chris Vale, Ben Upcroft, Adrian Ratnapala, Stuart Holt, Tom Campey, Otto Vainio, Matt Davis, Norman Heckenberg and Halina Rubinsztein-Dunlop
On 20th February 2004 the atom optics group at the University of Queensland produced a Bose-Einstein condensate on their home made atom chip (see figure and J Phys B 37,2959, 2004). Our first condensates contained a modest 20,000 rubidium 87 atoms in the |F=2,mF=+2> state. Since then (and after a fire forced us to move our lab) we have managed to produce larger condensates of up to 200,000 atoms in both the |2,2> and |1,-1> ground states of Rb. Typical magnetic trapping frequencies are 500Hz radially and 10Hz axially. The images (taken after 18ms time of flight) show the transition from a thermal cloud of 260,000 atoms to a near pure BEC of 100,000 atoms.