1301.7260 (H. Mäkelä et al.)

Excitation spectrum of a toroidal spin-1 Bose-Einstein condensate    [PDF]

H. Mäkelä, E. Lundh

We calculate analytically the excitation spectrum of a toroidal spin-1 Bose-Einstein condensate that is subjected to a homogeneous magnetic field and contains vortices with arbitrary winding numbers in the $m_F=\pm 1$ components of the hyperfine spin. The spectrum can be tuned by varying external parameters, such as the strength of the magnetic field. A rotonlike spectrum can be obtained, or an initially stable condensate can be made unstable by adjusting the magnitude of the magnetic field or trapping frequencies. The structure of the instabilities can be analyzed by measuring the particle density of the spin components.

View original: http://arxiv.org/abs/1301.7260