Bose–Einstein condensates in concentrically coupled annular traps with spin–orbit coupling and rotation

• In our manuscript, we studied Bose–Einstein condensates in concentrically coupled annular traps with spin–orbit coupling and rotation. The highlights are given as follows:
• The special shape of the external potential supports various ground state phases.
• Both spin–orbit coupling and rotation are considered.
• Not only spin–orbit coupling, but also rotation, can be used to induce the desired ground state phases.
• The method can be extended to investigate spin-1 condensates in various external potentials.

We investigate Bose–Einstein condensates in concentrically coupled annular traps with spin–orbit coupling and rotation. The ground state wave functions are computed by minimizing the Gross–Pitaevskii energy functional, and the combined effects of systemʼs parameters, especially the spin–orbit coupling and rotating, are investigated. The results show that for a finite fixed spin–orbit coupling, with increasing the angular frequency of rotation, the system is always in phase coexistence. Moreover, phase transitions between different ground state phases can be induced not only by spin–orbit coupling, but also rotation, which resembles very much the one where the s-wave interactions are varied.