Cold Atoms
Department of Molecular and Optical Physics - University of Freiburg, Germany.

Ejection of magnetic-field-sensitive atoms from an optical dipole trap
C. Käfer, R. Bourouis, J. Eurisch, A. Tripathi and Hanspeter Helm
Institute of Physics, Albert Ludwigs University, Hermann-Herderstrasse 3, D-79104 Freiburg, Germany

Phys. Rev. A 80, 023409 (2009) [8 pages]


Rubidium atoms prepared by evaporative cooling in an optical dipole trap are used in Stern-Gerlach type experiments. The analysis of the magnetic state distribution in the trap and during free fall demonstrates the possibility of ejecting all atoms with mF≠0 from the optical dipole trap. This is achieved by applying an appropriately located inhomogeneous magnetic field. We investigate the dynamics of this cleaning process, and record the temporal history of atom positions under the combined action of magnetic field and dipole-trap potential. The experimental findings are fully supported by realistic numerical simulations of the atomic dynamics. We show that analysis of the ejected atoms provides a means for nondestructive thermometry of a trapped atom cloud.

©2009 The American Physical Society

DOI: 10.1103/PhysRevA.80.023409
PACS: 37.10.Vz, 37.10.Gh, 32.60.+i, 71.70.Ej

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