TITLE:

MATTER WAVE VORTICES: THE QUANTUM SPIROGRAPH

DATE:

Friday, Feb 3rd, 2012

TIME:

3:30 PM

LOCATION:

GMCS 214

SPEAKER:

Ricardo Carretero.
Nonlinear Dynamical Systems group (NLDS).
Department of Mathematics and Statistics.
Computational Science Research Center.
San Diego State University.

ABSTRACT:

Motivated by recent experiments studying the dynamics of configurations
bearing a small number of vortices in atomic Bose-Einstein condensates
(BECs), we illustrate that such systems can be accurately described by
ordinary differential equations (ODEs) incorporating (a) vortex precession
induced by the harmonic trap confining the BEC and (b) vortex-vortex
interactions. The dynamics is studied in detail at the ODE level, both
for the equal and opposite charge vortex pairs. Co-rotating steady
states are identified about which perturbations lead to spirographic
(epitrochoidal) motion with excellent agreement with experimental
observations. A detailed analysis of the ensuing ODEs reveals the
possibility of stable asymmetric states bifurcating from symmetric ones.
Cases with more than two vortices are also discussed.

HOST:

Dr. Jose Castillo.

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