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Title: Compact setup for the production of {sup 87}Rb |F = 2, m{sub F} = + 2〉 Bose-Einstein condensates in a hybrid trap

Abstract

We present a compact experimental apparatus for Bose-Einstein condensation of {sup 87}Rb in the |F  =  2, m{sub F} = + 2〉 state. A pre-cooled atomic beam of {sup 87}Rb is obtained by using an unbalanced magneto-optical trap, allowing controlled transfer of trapped atoms from the first vacuum chamber to the science chamber. Here, atoms are transferred to a hybrid trap, as produced by overlapping a magnetic quadrupole trap with a far-detuned optical trap with crossed beam configuration, where forced radiofrequency evaporation is realized. The final evaporation leading to Bose-Einstein condensation is then performed by exponentially lowering the optical trap depth. Control and stabilization systems of the optical trap beams are discussed in detail. The setup reliably produces a pure condensate in the |F = 2, m{sub F} = + 2〉 state in 50 s, which includes 33 s loading of the science magneto-optical trap and 17 s forced evaporation.

Authors:
; ; ; ;  [1]
  1. Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)
Publication Date:
OSTI Identifier:
22597710
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 87; Journal Issue: 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ATOMIC BEAMS; ATOMS; BOSE-EINSTEIN CONDENSATION; COLLIDING BEAMS; DEPTH; EVAPORATION; LOADING; RADIOWAVE RADIATION; RUBIDIUM 87; TRAPS

Citation Formats

Nolli, Raffaele, Venturelli, Michela, Marmugi, Luca, E-mail: l.marmugi@ucl.ac.uk, Wickenbrock, Arne, and Renzoni, Ferruccio. Compact setup for the production of {sup 87}Rb |F = 2, m{sub F} = + 2〉 Bose-Einstein condensates in a hybrid trap. United States: N. p., 2016. Web. doi:10.1063/1.4960395.
Nolli, Raffaele, Venturelli, Michela, Marmugi, Luca, E-mail: l.marmugi@ucl.ac.uk, Wickenbrock, Arne, & Renzoni, Ferruccio. Compact setup for the production of {sup 87}Rb |F = 2, m{sub F} = + 2〉 Bose-Einstein condensates in a hybrid trap. United States. doi:10.1063/1.4960395.
Nolli, Raffaele, Venturelli, Michela, Marmugi, Luca, E-mail: l.marmugi@ucl.ac.uk, Wickenbrock, Arne, and Renzoni, Ferruccio. 2016. "Compact setup for the production of {sup 87}Rb |F = 2, m{sub F} = + 2〉 Bose-Einstein condensates in a hybrid trap". United States. doi:10.1063/1.4960395.
@article{osti_22597710,
title = {Compact setup for the production of {sup 87}Rb |F = 2, m{sub F} = + 2〉 Bose-Einstein condensates in a hybrid trap},
author = {Nolli, Raffaele and Venturelli, Michela and Marmugi, Luca, E-mail: l.marmugi@ucl.ac.uk and Wickenbrock, Arne and Renzoni, Ferruccio},
abstractNote = {We present a compact experimental apparatus for Bose-Einstein condensation of {sup 87}Rb in the |F  =  2, m{sub F} = + 2〉 state. A pre-cooled atomic beam of {sup 87}Rb is obtained by using an unbalanced magneto-optical trap, allowing controlled transfer of trapped atoms from the first vacuum chamber to the science chamber. Here, atoms are transferred to a hybrid trap, as produced by overlapping a magnetic quadrupole trap with a far-detuned optical trap with crossed beam configuration, where forced radiofrequency evaporation is realized. The final evaporation leading to Bose-Einstein condensation is then performed by exponentially lowering the optical trap depth. Control and stabilization systems of the optical trap beams are discussed in detail. The setup reliably produces a pure condensate in the |F = 2, m{sub F} = + 2〉 state in 50 s, which includes 33 s loading of the science magneto-optical trap and 17 s forced evaporation.},
doi = {10.1063/1.4960395},
journal = {Review of Scientific Instruments},
number = 8,
volume = 87,
place = {United States},
year = 2016,
month = 8
}
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  • The fragmentation of the ground state of a repulsive condensate immersed into a double-trap potential is found to be a general and critical phenomenon. It takes place for a given number of bosons if their scattering length is larger than some critical value or for a given value of the scattering length if the number of bosons is above some critical number. We demonstrate that the geometry of the inner trap determines these critical parameters while the number of the fragments and the fraction of bosons in the various fragments can be manipulated by the outer trap. There is alsomore » a maximal number of bosons for which the ground state is fragmented. If this number is exceeded, the fragmented state becomes a very low-lying excited state of the condensate. This maximal number of bosons can be substantially manipulated by varying the inner and outer traps. To study threefold fragmentation we have chosen a potential well with two barriers as the inner trap and embedded in two types of outer ones. A manifold fragmentation is also addressed.« less