Communications on Pure & Applied Analysis
Vortex interaction dynamics in trapped Bose-Einstein condensates
Pedro J. Torres, R. Carretero-González, Stephan Middelkamp, Peter Schmelcher, D. J. Frantzeskakis, P. G. Kevrekidis
Abstract
Motivated by recent experiments studyingthe dynamics ofconfigurations bearing a small number of vortices inatomic Bose-Einstein condensates (BECs), weillustrate that such systems can be accurately described byordinary differential equations (ODEs) incorporating the precessionand interaction dynamics ofvortices inharmonic traps.This dynamics is tackled in detail at the ODE level, both forthe simpler case of equal charge vortices,and for the more complicated(yet also experimentally relevant) case of opposite charge vortices.In the former case, we identify the dynamics as being chieflyquasi-periodic (although potentially periodic), while in thelatter, irregular dynamics may ensuewhen suitableexternal drive of the BEC cloud is also considered. Our analytical findings arecorroborated by numerical computations of the reduced ODE system.