High repetition rate Bose-Einstein condensate production in a compact, transportable vacuum system

Author
Abstract
<p>This thesis reports on the design and implementation of a compact (5 \texttimes 10 \texttimes 30 cm) two chamber system for rapidly producing 87Rb Bose-Einstein condensates (BEC) on an atom chip with the future goal of a transportable BEC based sensor. We present the first use of anodic bonding to fabricate multi-chamber vacuum systems suitable for BEC production. Anodic bonding is a method for joining silicon and Pyrex and is superior to epoxy based construction because anodically bonded vacuum systems can be baked at temperatures \&gt; 300\textdegreeC. The improved vacuum quality is a key aspect of reproducibly building compact BEC quality vacuum systems. In the two chamber vacuum system the first chamber operates a 2D+ magneto-optical trap (MOT) at a Rb pressure of ~ 10-7 torr and produces a flux of cold atoms that loads a 3D MOT in the second, low pressure (\&lt; 10-9 torr) chamber. When loaded to saturation the 3D MOT contains ~ 500 \texttimes 106 87Rb atoms. The laser cooled atoms are magnetically transferred to an atom chip where the atoms are cooled to degeneracy by forced RF evaporation in a tight magnetic trap (1.8\texttimes3.0\texttimes0.6 kHz). The system performance is demonstrated by three modes: the rapid production of sequential BECs of 1 \texttimes 105 atoms with a period of \&lt; 3.8 s, the number optimized production of a BEC of 4 \texttimes 105 atoms in \&lt; 10 s, and the speed optimized production of a BEC of 5\texttimes104 atoms in 2.65 s. Initial experiments demonstrating key elements of rotation sensor are also presented. Specifically splitting atoms on a chip in a compact vacuum system and guiding atoms around a curve. Also presented in this thesis is a rubidium dispenser based on a gold/rubidium alloy that has potential as a clean source of rubidium in cold atom experiments.</p>
Year of Publication
2008
University
University of Colorado Boulder
City
Boulder
Advisors - JILA Fellows
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