期刊
PHYSICAL REVIEW B
卷 80, 期 1, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.80.014523
关键词
band structure; d-wave superconductivity; electronic density of states; exchange interactions (electron); Fermi level; flux-line lattice; iron compounds; localised states; resonant states; scanning tunnelling microscopy; spin density waves; tight-binding calculations
资金
- U. S. DOE [1146, DE-AC52-06NA25396]
The pairing symmetry is one of the major issues in the study of iron-based superconductors. We adopt a minimal two-band tight-binding model with various channels of pairing interaction, and derive a set of two-band Bogoliubov-de Gennes (BdG) equations. The BdG equations are implemented in real space and then solved self-consistently via exact diagonalization. In the uniform case, we find that the d(x)(2)-y(2)-wave pairing state is most favorable for a nearest-neighbor pairing interaction while the s(x)(2)y(2)-wave pairing state is most favorable for a next-nearest-neighbor pairing interaction, which is consistent with that reported by Seo [Phys. Rev. Lett. 101, 206404 (2008)]. We then proceed to study the local electronic structure around a magnetic vortex core for both d(x)(2)-y(2)-wave and s(x)(2)y(2)-wave pairing symmetry in the mixed state. It is found from the local density of states spectra and its spatial variation that the resonance core states near the Fermi energy for the d(x)(2)-y(2)-wave pairing symmetry are bound while those for the s(x)(2)y(2)-wave pairing symmetry can evolve from the localized states into extended ones with varying electron filling factor. Furthermore, by including an effective exchange interaction, the emergent antiferromagnetic spin-density-wave order can suppress the resonance core states, which provides one possible avenue to understand the absence of resonance peak as revealed by recent scanning tunneling microscopy experiment by Yin [Phys. Rev. Lett. 102, 097002 (2009)].
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据