Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phenomenological Models for the Gap Anisotropy of Bi-2212 as Measured by
  ARPES   Recently, high resolution angle-resolved photoemission spectroscopy has been
used to determine the detailed momentum dependence of the superconducting gap
in the high temperature superconductor Bi-2212. In this paper, we first
describe tight binding fits to the normal state dispersion and superlattice
modulation effects. We then discuss various theoretical models in light of the
gap measurements. We find that the simplest model which fits the data is the
anisotropic s-wave gap $\cos(k_x)\cos(k_y)$, which within a one-band BCS frame-
work suggests the importance of next near neighbor Cu-Cu interactions. Various
alternative interpretations of the observed gap are also discussed, along with
the implications for microscopic theories of high temperature superconductors.

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The categories of this paper are: physics
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
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The categories of this paper are: math
8
The categories of this paper are: hep-ex
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The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
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The categories of this paper are: hep-th
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The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys