Browsing by Subject "Vortex lattices"
Now showing 1 - 5 of 5
- Results Per Page
- Sort Options
Item Open Access Pairing and vortex lattices for interacting fermions in optical lattices with a large magnetic field(The American Physical Society, 2010) Zhai, H.; Umucalılar, R. O.; Oktel, M. Ö.We study the structure of a pairing order parameter for spin-1/2 fermions with attractive interactions in a square lattice under a uniform magnetic field. Because the magnetic translation symmetry gives a unique degeneracy in the single-particle spectrum, the pair wave function has both zero and finite-momentum components coexisting, and their relative phases are determined by a self-consistent mean-field theory. We present a microscopic calculation that can determine the vortex lattice structure in the superfluid phase for different flux densities. Phase transition from a Hofstadter insulator to a superfluid phase is also discussed.Item Open Access Photonic band gap in the triangular lattice of Bose-Einstein-condensate vortices(2007) Taşgin, M. E.; Müstecaplioǧlu Ö. E.; Oktel, M. Ö.We investigate the photonic bands of an atomic Bose-Einstein condensate with a triangular vortex lattice. Index contrast between the vortex cores and the bulk of the condensate is achieved through the enhancement of the index via atomic coherence. The frequency-dependent dielectric function is used in the calculations of the bands, resulting in photonic band gap widths of a few megahertz. © 2007 The American Physical Society.Item Open Access Vortex lattice of a Bose-Einstein condensate as a photonic band gap material(IOP Institute of Physics Publishing, 2009) Taşgin, M. E.; Müstecaplioǧlu, Ö. E.; Oktel, M. Ö.Photonic crystal behavior of a rotating Bose-Einstein condensate with a triangular vortex lattice is reviewed and a scheme for getting much wider band gaps is proposed. It is shown that photonic band gaps can be widened an order of magnitude more by using a Raman scheme of index enhancement, in comparison to previously considered upper level microwave scheme.Item Open Access Vortex lattice of a Bose-Einstein condensate in a rotating anisotropic trap(American Physical Society, 2004) Oktel, M. Ö.The behavior of Bose-Einstein condensates (BEC) with a vortex lattice in a rotating anisotropic trap was studied. The single-particle wave functions for a rotating anisotropy trap were found by exactly diagonalizing the Hamiltonian. The wave functions in the lowest Landau level (LLL) were shown to be written as simple analytic functions in the small anisotropy limit. The results show that the regularity of the vortex configurations observed in an axisymmetric trap is disturbed by the anisotropy of the confinement.Item Open Access Vortex lattices in dipolar two-compenent Bose-Einstein condensates(American Physical Society, 2014-02-21) Ghazanfari, N.; Keles, A.; Oktel, M. O.We consider a rapidly rotating two-component Bose-Einstein condensate with short-range s-wave interactions as well as dipolar coupling. We calculate the phase diagram of vortex lattice structures as a function of the intercomponent s-wave interaction and the strength of the dipolar interaction. We find that the long-range interactions cause new vortex lattice structures to be stable and lead to a richer phase diagram. Our results reduce to the previously found lattice structures for short-range interactions and single-component dipolar gases in the corresponding limits.