SELF-CONSISTENT ELECTRONIC-STRUCTURE OF A VORTEX LINE IN A TYPE-II SUPERCONDUCTOR
SELF-CONSISTENT ELECTRONIC-STRUCTURE OF A VORTEX LINE IN A TYPE-II SUPERCONDUCTOR
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DOI：
10.1103/physrevb.43.7609
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发表时间：
1991-04-01
影响因子：
3.7
通讯作者：
SCHLUTER, M
中科院分区：
文献类型：
--
作者：
GYGI, F;SCHLUTER, M
在Bogoliubov-de Gennes理论框架下，对第二类超导体中涡旋线的电子结构进行了自洽计算。用电子-电子吸引相互作用的德拜频率、费米速度和耦合常数作为微观输入参数。由此产生的准粒子激发谱、对电势和电流分布作为温度的函数被研究，并且可以用来定义相干长度和确定磁穿透深度。由准粒子振幅计算的单粒子激发的局域密度解释了Hess等人的扫描隧道显微镜(STM)实验结果。[物理。莱特牧师。62,214(1989)]NbSe2。实验结果中的主要光谱特征是由涡核中的束束态引起的。用一个简化的双带模型讨论了由相邻涡旋和晶格引起的束缚态波函数的空间扭曲。在NbSe2的情况下，得到的局域态密度在真实空间中具有特征的星形，其取向与能量有关，这与最近的STM实验[物理。莱特牧师。，第2711(1990)号。
The electronic structure of a vortex line in a type-II superconductor is calculated self-consistently in the framework of the Bogoliubov-de Gennes theory. The Debye frequency, the Fermi velocity, and the coupling constant of the electron-electron attractive interaction are used as microscopic input parameters. The resulting quasiparticle-excitation spectrum, the pair potential, and the current distribution are studied as a function of temperature, and can be used to define a coherence length and to determine the magnetic penetration depth. The local density of one-particle excitations, calculated from the quasiparticle amplitudes, explains the results of scanning-tunneling-microscopy (STM) experiments by Hess et al. [Phys. Rev. Lett. 62, 214 (1989)] on NbSe2. The main spectroscopic features in the experimental results are caused by bound states in the vortex cores. Spatial distortions of the bound-state wave functions caused by neighboring vortices and by the crystalline lattice are discussed in terms of a simplified two-band model. In the case of NbSe2, the resulting local density of states has a characteristic star shape in real space, whose orientation is energy dependent, in agreement with recent STM experiments [Phys. Rev. Lett. 64, 2711 (1990)].