title: New Andreev-type states in superconducting nanowires.
abstract: Superconducting nanowires can exhibit a spatially inhomogeneous pair condensate that leads to the formation of new Andreev-type states. Such states are mainly located beyond the regions where the order parameter is enhanced, and no normal-superconducting contact or external magnetic field is needed for their formation. Our numerical self-consistent solutions of the Bogoliubov-de Gennes equations for cylindrical nanowires, in the clean limit, demonstrate that these new Andreev-type states decrease the ratio of the energy gap to the critical temperature as compared to its bulk value. The low-lying excitations in a clean superconducting nanowire are these new Andreev-type states induced by quantum confinement of the electrons in the transverse direction.
authors.affiliation: TGM, Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium.
authors.forename: A A
authors.initials: AA
authors.lastname: Shanenko
authors.forename: M D
authors.initials: MD
authors.lastname: Croitoru
authors.forename: R G
authors.initials: RG
authors.lastname: Mints
authors.forename: F M
authors.initials: FM
authors.lastname: Peeters