Bose-Einstein condensate of a mixture of two species of spin-1 atoms

Abstract

The interaction between two species of atoms in the condensate has been deduced and the trial wave functions that conserve the total spin have been constructed for the states of the ground band. A couple of generalized Gross-Pitaevskii equations have been derived for the spatial wave functions and the energies. The mixture of 23 Na and 87 Rb has been calculated as an example. The density of states is found to exhibit a ladder shape.

Interspecies singlet pairing in a mixture of two spin-1 Bose condensates

“…By adjusting the two s-wave scattering lengths a 0 and a 2 through the so-called optical Feshbach resonances [24], the spin-exchange interaction between individual atoms can be precisely tuned. The theoretical studies on mixtures of spinor condensates attracted much attention recently and both mean-field and quantum many-body theories have been applied to this novel system [25][26][27][28][29]. A temporal modulation of spin-exchange interaction, which is tunable with optical Feshbach resonance, was recently proposed to localize the spin mixing dynamics in a 87 Rb condensate [30].…”

Coherent Heteronuclear Spin Dynamics in an Ultracold Spinor Mixture

“…Our study brings out several unique features of the spinor mixtures. (1) For collisions between two distinguishable spin-1 atoms, the interaction takes place over all three total spin F = 0, 1 and 2 channels [18][19][20][21][22][23][24], while only F = 0 and 2 are allowed for homonuclear collisions. (2) Unlike the single species case, where only quadratic Zeeman effect is important due to magnetization conservation [25], in spinor mixtures, both linear and quadratic Zeeman effects are important.…”

Fragmentation of a spin-1 mixture in a magnetic field

“…The inter-condensate interaction between the ferromagnetic and polar atoms is V 12 (r) = When the interspecies scattering parameters are calculated in the degenerate internal-state approximation (DIA) [24][25][26][27], the low-energy atomic interactions can be mostly attributed to the ground-state configurations of the two valence electrons, and the non-commutative term Θ † 12Θ 12 can be neglected [6,7,9]. The ground states are classified into four distinct phases: FF, MM − , MM + , and AA by three critical values of c 12 β = − (2N −1)c2β2 N , 0, and…”

“…With the basic interaction form V (r) = (α+βF·F)δ(r), the properties of such a three-component spinor condensate [4] have been demonstrated experimentally [5] and two different phases reflecting fundamental properties of spin correlation are identified: the so-called polar and ferromagnetic states for β > 0 ( 23 Na) and β < 0 ( 87 Rb) atomic condensates respectively. The mixture of two spinor condensate with the ferromagnetic and polar atoms, respectively, show more attractive quantum effects [6][7][8][9][10][11][12][13][14][15]. With the help of sympathetic cooling, the BEC mixtures of Na and Rb have been realized and it is interesting to observe the interspecies interaction induced immiscibility between the two condensates [15].…”