Vortex lines in a ferromagnetic spin-triplet superconductor  

作　　者：赵力 杨捷 谢群英 田苗 段一士 

机构地区：[1]Institute of Theoretical Physics,Lanzhou University [2]School of Information Science and Engineering,Lanzhou University [3]School of Mathematics,Physics and Software Engineering,Lanzhou Jiaotong University

出　　处：《Chinese Physics B》2012年第5期616-624,共9页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.10905026 and 10905027);the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20090211120030);the Lanzhou Development of Science and Technology Program,China(Grant No.2010-1-129)

摘　　要：Based on Duan’s topological current theory,we show that in a ferromagnetic spin-triplet superconductor there is a topological defect of string structures which can be interpreted as vortex lines.Such defects are different from the Abrikosov vortices in one-component condensate systems.We investigate the inner topological structure of the vortex lines.The topological charge density,velocity,and topological current of the vortex lines can all be expressed in terms of δ function,which indicates that the vortices can only arise from the zero points of an order parameter field.The topological charges of vortex lines are quantized in terms of the Hopf indices and Brouwer degrees of-mapping.The divergence of the self-induced magnetic field can be rigorously determined by the corresponding order parameter fields and its expression also takes the form of a δ-like function.Finally,based on the implicit function theorem and the Taylor expansion,we conduct detailed studies on the bifurcation of vortex topological current and find different directions of the bifurcation.Based on Duan’s topological current theory,we show that in a ferromagnetic spin-triplet superconductor there is a topological defect of string structures which can be interpreted as vortex lines.Such defects are different from the Abrikosov vortices in one-component condensate systems.We investigate the inner topological structure of the vortex lines.The topological charge density,velocity,and topological current of the vortex lines can all be expressed in terms of δ function,which indicates that the vortices can only arise from the zero points of an order parameter field.The topological charges of vortex lines are quantized in terms of the Hopf indices and Brouwer degrees of-mapping.The divergence of the self-induced magnetic field can be rigorously determined by the corresponding order parameter fields and its expression also takes the form of a δ-like function.Finally,based on the implicit function theorem and the Taylor expansion,we conduct detailed studies on the bifurcation of vortex topological current and find different directions of the bifurcation.

关 键 词：vortex lines spin-triplet superconductor topological current BIFURCATION 

分 类 号：O4[理学—物理]