Ginzburg-Landau theory of vortices in a multigap superconductor
Ginzburg-Landau theory of vortices in a multigap superconductor
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DOI：
10.1103/physrevb.69.054508
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发表时间：
2003-09
影响因子：
3.7
通讯作者：
M. Zhitomirsky;V. Dao
中科院分区：
文献类型：
--
作者：
M. Zhitomirsky;V. Dao
在弱耦合BCS模型中推导了双间隙超导体的金兹堡-朗道泛函。两种凝析油之间的相互作用用一个独特的约瑟夫森型混合项来描述。然后应用双间隙金兹堡-朗道理论研究了${\ mathm {MgB}}_{2}$的各种磁性，包括横向上临界场的上升温度依赖性和孤立涡旋的核心结构。研究了平行于c轴的磁场下涡旋晶格相对于结晶轴的取向。中子散射观测到的旋涡晶格随着外加电场强度的增加而发生的特殊$30\ifmmode^\circ\else\textdegree\fi{}$旋转归因于${\ mathm {MgB}}_{2}.$中超导的多间隙性质
The Ginzburg-Landau functional for a two-gap superconductor is derived within the weak-coupling BCS model. The interaction between the two condensates is described by a unique Josephson-type mixing term. The two-gap Ginzburg-Landau theory is then applied to investigate various magnetic properties of ${\mathrm{MgB}}_{2}$ including an upturn temperature dependence of the transverse upper critical field and a core structure of an isolated vortex. The orientation of vortex lattice relative to crystallographic axes is studied for magnetic fields parallel to the c axis. A peculiar $30\ifmmode^\circ\else\textdegree\fi{}$ rotation of the vortex lattice with increasing strength of an applied field observed by neutron scattering is attributed to the multigap nature of superconductivity in ${\mathrm{MgB}}_{2}.$