Journal ArticleDOI
Anomalously large gap anisotropy in the a - b plane of Bi 2 Sr 2 CaCu 2 O 8 + δ
Zhi-Xun Shen,Zhi-Xun Shen,Daniel Dessau,Daniel Dessau,Barrett Wells,Barrett Wells,D. M. King,D. M. King,W. E. Spicer,W. E. Spicer,A. J. Arko,A. J. Arko,Daniel S. Marshall,Daniel S. Marshall,L. W. Lombardo,L. W. Lombardo,Aharon Kapitulnik,Aharon Kapitulnik,P. H. Dickinson,P. H. Dickinson,Sebastian Doniach,Sebastian Doniach,J. DiCarlo,J. DiCarlo,T. Loeser,T. Loeser,C. H. Park,C. H. Park +27 more
TLDR
In this paper, the gap size reaches a maximum of approximately 20 meV along the Cu-O bond direction, and a minimum of much smaller or vanishing magnitude 45\ifmmode^\circ\else\text degree\fi{} away.Abstract:
Superconducting gap anisotropy at least an order of magnitude larger than that of the conventional superconductors has been observed in the a-b plane of ${\mathrm{Bi}}_{2}$${\mathrm{Sr}}_{2}$${\mathrm{CaCu}}_{2}$${\mathrm{O}}_{8+\mathrm{\ensuremath{\delta}}}$ in angle-resolved photoemission spectroscopy. For samples with ${\mathit{T}}_{\mathit{c}}$ of 88 K, the gap size reaches a maximum of approximately 20 meV along the Cu-O bond direction, and a minimum of much smaller or vanishing magnitude 45\ifmmode^\circ\else\textdegree\fi{} away. The experimental data are discussed within the context of various theoretical models. In particular, a detailed comparison with what is expected from a superconductor with a ${\mathit{d}}_{\mathit{x}}^{2}$-${\mathit{y}}^{2}$ order parameter is carried out, yielding a consistent picture.read more
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Journal ArticleDOI
Angle-resolved photoemission studies of the cuprate superconductors
TL;DR: A review of the most recent ARPES results on the cuprate superconductors and their insulating parent and sister compounds is presented in this article, with the purpose of providing an updated summary of the extensive literature.
Journal ArticleDOI
Spectroscopic evidence for a pseudogap in the normal state of underdoped high- T c superconductors
Hong Ding,Hong Ding,Takayoshi Yokoya,Juan Carlos Campuzano,Juan Carlos Campuzano,Tetsuo Takahashi,Mohit Randeria,Michael R. Norman,T. Mochiku,Kazuo Kadowaki,John Giapintzakis +10 more
TL;DR: In this paper, a study of underdoped Bi2Sr2CaCu2O8+δ (Bi2212) using angle-resolved photoemission spectroscopy (ARPES) is presented.
Journal ArticleDOI
Tunnelling effects on surface bound states in unconventional superconductors
Satoshi Kashiwaya,Yukio Tanaka +1 more
TL;DR: In this paper, it is clarified theoretically that the observed ZBCPs reflect the formation of zero-energy states on the surface due to the?-phase shift of internal phase in the d-wave pairing symmetry.
Journal ArticleDOI
Dirac materials
TL;DR: A wide range of materials, such as d-wave superconductors, graphene, and topological insulators, share a fundamental similarity: their low-energy fermionic excitations behave as massless Dirac particles rather than fermions obeying the usual Schrodinger Hamiltonian as mentioned in this paper.
Journal ArticleDOI
The case for dx2 − y2 pairing in the cuprate superconductors
TL;DR: In this article, the authors examined the possibility that the superconducting state of these materials is characterized by d x 2 − y 2 pairing and showed that this type of pairing might be favored in a strongly correlated system with a short-range Coulomb interaction.