Li (Lee), Chaohong2009-10-202010-12-202009-10-202010-12-20Physical Review Letters 102.7 (2009): 070401/1-40031-90071079-7114http://hdl.handle.net/10440/953http://digitalcollections.anu.edu.au/handle/10440/953We study both mean-field and full quantum dynamics of symmetry-breaking transitions (SBTs) in a coupled two-component Bose-Einstein condensate. By controlling s-wave scattering lengths and the coupling strength, it is possible to stimulate SBTs between normal and spontaneously polarized ground states. In static transitions, the probability maxima of full quantum ground states correspond to the mean-field ground states. In dynamical transitions, due to the vanishing of excitation gaps, the mean-field dynamics shows universal scalings obeying the Kibble-Zurek mechanism. Both mean-field and full quantum defect modes appear as damped oscillations, but they appear at different critical points and undergo different oscillation regimes. The anomalous breakdown of mean-field dynamics induced by SBTs depends on the approaching direction.4 pageshttp://www.sherpa.ac.uk/romeo/index.php "Author can archive pre-print (ie pre-refereeing) … post-print (ie final draft post-refereeing) … [and] publisher's version/PDF. Link to publisher version … [and] Copyright notice required. Publisher's version/PDF can be used on … employers web site." - from SHERPA/RoMEO site (as at 25/02/10). ©2009 The American Physical SocietyKeywords: Bose-Einstein condensation; Equations of state; Ground state; Semiconductor quantum dots; Steam condensers; Bose- Einstein condensates; Coupling strengths; Critical points; Damped oscillations; Dynamical transitions; Excitation gaps; Kibble-Zurek mechanis2009-02-1810.1103/PhysRevLett.102.0704012016-02-24