title: Vortex charges in high-temperature superconductors.
abstract: Based on a model Hamiltonian with competing antiferromagnetic (AF) and d-wave superconductivity interactions, the vortex charge is investigated by solving the Bogoliubov-de Gennes equations. We found that the vortex charge is negative when a sufficient strength of AF order is induced inside the vortex core; otherwise, it is positive. By tuning the on-site Coulomb repulsion U or the doping parameter delta, a transition between the positive and negative vortex charges may occur. The vortex charge at optimal doping has also been studied as a function of magnetic field. Recent NMR and Hall effect experiments may be understood in terms of the present results.
authors.affiliation: Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, Texas 77204, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.forename: Z D
authors.initials: ZD
authors.lastname: Wang
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Zhu
authors.forename: C S
authors.initials: CS
authors.lastname: Ting