Blue-detuned optical ring trap for Bose-Einstein condensates based on conical refraction

We present a novel approach for the optical manipulation of neutral atoms in annular light structures produced by the phenomenon of conical refraction occurring in biaxial optical crystals. For a beam focused to a plane behind the crystal, the focal plane exhibits two concentric bright rings enclosi...

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Bibliographic Details
Authors: Turpin Avilés, Alejandro|||0000-0001-7877-782X, Polo Gómez, Juan|||0000-0003-0742-6015, Loiko, Yu V., Küber, Johannes, Schmaltz, F., Kalkandjiev Ganchev, Todor|||0000-0002-6039-7586, Ahufinger, Verònica|||0000-0002-6628-9930, Birkl, Gerhard, Mompart Penina, Jordi|||0000-0002-9634-9455
Format: article
Publication Date:2015
Country:España
Institution:Universitat Autònoma de Barcelona
Repository:Dipòsit Digital de Documents de la UAB
Language:English
OAI Identifier:oai:ddd.uab.cat:203902
Online Access:https://ddd.uab.cat/record/203902
https://dx.doi.org/urn:doi:10.1364/OE.23.001638
Access Level:Open access
Keyword:Analytical expressions
Bose-Einstein condensates
Conical refraction
Light structures
Optical crystals
Optical manipulation
Three dimensions
Trapping frequency
Description
Summary:We present a novel approach for the optical manipulation of neutral atoms in annular light structures produced by the phenomenon of conical refraction occurring in biaxial optical crystals. For a beam focused to a plane behind the crystal, the focal plane exhibits two concentric bright rings enclosing a ring of null intensity called the Poggendorff ring. We demonstrate both theoretically and experimentally that the Poggendorff dark ring of conical refraction is confined in three dimensions by regions of higher intensity. We derive the positions of the confining intensity maxima and minima and discuss the application of the Poggendorff ring for trapping ultra-cold atoms using the repulsive dipole force of blue-detuned light. We give analytical expressions for the trapping frequencies and potential depths along both the radial and the axial directions. Finally, we present realistic numerical simulations of the dynamics of a ⁸⁷Rb Bose-Einstein condensate trapped inside the Poggendorff ring which are in good agreement with corresponding experimental results.