摘要
Vortices in the N-gap （N ≥ 1） superconductor is studied by Dirac δ function. The topological structure of vortices can be characterized by Brouwer degree and Hopf index, i.e. （βtη1,… , βNηN ）. The magnetic flux and circulation of vortices without London approximation in the N-gap superconductor are calculated. The universal modified London equation is given for the case that each individual condensate is conserved or not conserved.
基金
Supported by the National Natural Science Foundation of China under Grant No.10805022
