QUASIPARTICLES OF D-WAVE SUPERCONDUCTORS IN FINITE MAGNETIC FIELDS
QUASIPARTICLES OF D-WAVE SUPERCONDUCTORS IN FINITE MAGNETIC FIELDS
复制标题
有限磁场中 D 波超导体的准粒子
DOI：
10.1103/physrevlett.83.4168
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发表时间：
1999
影响因子：
8.6
通讯作者：
T. Kita
中科院分区：
文献类型：
--
作者：
Kouji Yasui;T. Kita
通过自洽求解Bogoliubov-de Gennes方程，研究了涡旋晶格中d波超导体的准粒子。对于纯d_{x^2-y^2}$态，发现：（i）即使在低磁场下，磁布里渊区中的低能准粒子带也有较大的色散，表明孤立涡旋不存在束缚态;（ii）在k_F\xi_0 $较小的有限场中，计算得到的涡核隧穿电导在零偏压附近呈现双峰结构，定性地与Maggio-Aprile等人的STM实验一致[Phys.Rev.Lett.（1995）2754]。我们还发现d_{xy}$-或s-波分量的混合，如果有的话，随着场的增加逐渐发展而没有跃迁，对隧穿谱的影响很小。
We study quasiparticles of d-wave superconductors in the vortex lattice by self-consistently solving the Bogoliubov-de Gennes equations. It is found for a pure $d_{x^2-y^2}$ state that: (i) low-energy quasiparticle bands in the magnetic Brillouin zone have rather large dispersion even in low magnetic fields, indicating absense of bound states for an isolated vortex; (ii) in finite fields with $k_F \xi_0$ small, the calculated tunneling conductance at the vortex core shows a double-peak structure near zero bias, as qualitatively consistent with the STM experiment by Maggio-Aprile et al. [Phys. Rev. Lett. {\bf 75} (1995) 2754]. We also find that mixing of a $d_{xy}$- or an s-wave component, if any, develops gradually without transitions as the field is increased, having little effect on the tunneling spectra.