Anatoly A. Svidzinsky — Page 3

arXiv1999

Vortex State Structure of a Bose Condensate in an Asymmetric Trap

Based on an analytic solution of the Gross-Pitaevskii equation in the large-condensate (Thomas-Fermi) limit we determine the structure of a stationary vortex in a Bose-Einstein condensate in a nonaxisymmetric rotating trap. The condensate velocity field has cylindrical symmetry only near the vortex core and becomes intrinsically anisotropic near the condensate boundaries. Rotating the anisotropic trap induces an additional irrotational velocity field even for a vortex-free condensate.

cond-mat.stat-mech↗

arXiv1996

Josephson and Quasiparticle Tunneling between Anisotropically Paired Superconductors

Charge transport in tunnel junctions between singlet anisotropically paired superconductors is investigated theoretically making use of the Eilenberger equations for the quasiclassical Green functions. For specularly reflecting tunnel barrier plane we have found and described analytically characteristic singular points of the I-V curves which are specific for the case of anisotropic pairing. All four terms for the electric current are examined. Two of them describe ac Josephson effect and two correspond to the quasiparticle current (the last term occurs only for a time-dependent voltage). Various momentum dependences of the order parameter in the bulk of superconductors and different crystal orientations are considered. The results of numerical calculations for the total I-V curves are presented for some particular cases.

cond-mat↗