Book Description

Abstract: The ground states of two-component miscible Bose–Einstein condensates (BECs) confined in a rotating annular trap are obtained by using the Thomas–Fermi (TF) approximation method. The ground state density distribution of the condensates experiences a transition from a disc shape to an annulus shape either when the angular frequency increases and the width and the center height of the trap are fixed, or when the width and the center height of the trap increase and the angular frequency is fixed. Meantime the numerical solutions of the ground states of the trapped two-component miscible BECs with the same condition are obtained by using imaginary-time propagation method. They are in good agreement with the solutions obtained by the TF approximation method. The ground states of the trapped two-component immiscible BECs are also given by using the imaginary-time propagation method. Furthermore, by introducing a normalized complex-valued spinor, three kinds of pseudospin textures of the BECs, i.e., giant skyrmion, coaxial double-annulus skyrmion, and coaxial three-annulus skyrmion, are found.