We perform a mean-field study of the binary Bose-Einstein condensate mixtures as a function of the mutual repulsive interaction strength. In the phase segregated regime, we find that there are two distinct phases: the weakly segregated phase characterized by a ``penetration depth'' and the strongly segregated phase characterized by a healing length. In the weakly segregated phase the symmetry of the shape of each condensate will not take that of the trap because of the finite surface tension, but its total density profile still does. In the strongly segregated phase even the total density profile takes a different symmetry from that of the trap because of the mutual exclusion of the condensates. The lower critical condensate-atom number to observe the complete phase segregation is discussed. A comparison to recent experimental data suggests that the weakly segregated phase has been observed.We perform a mean-field study of the binary Bose-Einstein condensate mixtures as a function of the mutual repulsive interaction strength. In the phase segregated regime, we find that there are two distinct phases: the weakly segregated phase characterized by a ``penetration depth'' and the strongly segregated phase characterized by a healing length. In the weakly segregated phase the symmetry of the shape of each condensate will not take that of the trap because of the finite surface tension, but its total density profile still does. In the strongly segregated phase even the total density profile takes a different symmetry from that of the trap because of the mutual exclusion of the condensates. The lower critical condensate-atom number to observe the complete phase segregation is discussed. A comparison to recent experimental data suggests that the weakly segregated phase has been observed.

arXiv:cond-mat/9809195Physical Review ADec 1, 1998329 citations

Phase-ordering percolation and an infinite domain wall in segregating binary Bose-Einstein condensates

Hiromitsu Takeuchi, Yumiko Mizuno, Kentaro Dehara

Percolation theory is applied to the phase-transition dynamics of domain pattern formation in segregating binary Bose-Einstein condensates in quasi-two-dimensional systems. Our finite-size-scaling analysis shows that the percolation threshold of the initial domain pattern emerging from the dynamic instability is close to 0.5 for strongly repulsive condensates. The percolation probability is universally described with a scaling function when the probability is rescaled by the characteristic domain size in the dynamic scaling regime of the phase-ordering kinetics, independent of the intercomponent interaction. It is revealed that an infinite domain wall sandwiched between percolating domains in the two condensates has a noninteger fractal dimension and keeps the scaling behavior during the dynamic scaling regime. This result seems to be in contrast to the argument that the dynamic scale invariance is violated in the presence of an infinite topological defect in numerical cosmology.Percolation theory is applied to the phase-transition dynamics of domain pattern formation in segregating binary Bose-Einstein condensates in quasi-two-dimensional systems. Our finite-size-scaling analysis shows that the percolation threshold of the initial domain pattern emerging from the dynamic instability is close to 0.5 for strongly repulsive condensates. The percolation probability is universally described with a scaling function when the probability is rescaled by the characteristic domain size in the dynamic scaling regime of the phase-ordering kinetics, independent of the intercomponent interaction. It is revealed that an infinite domain wall sandwiched between percolating domains in the two condensates has a noninteger fractal dimension and keeps the scaling behavior during the dynamic scaling regime. This result seems to be in contrast to the argument that the dynamic scale invariance is violated in the presence of an infinite topological defect in numerical cosmology.

arXiv:1505.02276Physical Review AOct 9, 201524 citations

Phase dynamics of the Bose–Einstein condensates

Weidong Li, Xiaoji Zhou, Y.Q. Wang +2 more

Physics Letters AJun 1, 20013 citations

Broken cylindrical symmetry in binary mixtures of Bose-Einstein condensates

S. T. Chui, Ping Ao

We provide Monte Carlo simulation and analytic interface arguments for the absence of cylindrical symmetry in the density difference of a binary mixture of Bose-Einstein condensates in traps in the phase segregated regime. For different spin states of ${}^{87}\mathrm{Rb},$ the total density remains very symmetric however. There is a metastable symmetric phase in a substantial part of this phase segregated regime. The boundary between the symmetric and the nonsymmetric phase is a function of the relative concentration. The effect of different confining potentials is investigated.We provide Monte Carlo simulation and analytic interface arguments for the absence of cylindrical symmetry in the density difference of a binary mixture of Bose-Einstein condensates in traps in the phase segregated regime. For different spin states of ${}^{87}\mathrm{Rb},$ the total density remains very symmetric however. There is a metastable symmetric phase in a substantial part of this phase segregated regime. The boundary between the symmetric and the nonsymmetric phase is a function of the relative concentration. The effect of different confining potentials is investigated.

Physical Review AFeb 1, 199938 citations

{}^{87}\mathrm{Rb},

the total density remains very symmetric however. There is a metastable symmetric phase in a substantial part of this phase segregated regime. The boundary between the symmetric and the nonsymmetric phase is a function of the relative concentration. The effect of different confining potentials is investigated.