Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: ARPES Spectral Function in Lightly Doped and Antiferromagnetically
  Ordered YBa2Cu3O{6+y}   At doping below 6% the bilayer cuprate YBa2Cu3O{6+y} is a collinear
antiferromagnet. Independent of doping the value of the staggered magnetization
at zero temperature is about 0.6\mu_B. This is the maximum value of the
magnetization allowed by quantum fluctuations of localized spins. In this low
doping regime the compound is a normal conductor with a finite resistivity at
zero temperature. These experimental observations create a unique opportunity
for theory to perform a controlled calculation of the electron spectral
function. In the present work we perform this calculation within the framework
of the extended t-J model. As one expects the Fermi surface consists of small
hole pockets centered at (\pi/2,\pi/2). The electron spectral function is very
strongly anisotropic with maximum of intensity located at the inner parts of
the pockets and with very small intensity at the outer parts. We also found
that the antiferromagnetic correlations act against the bilayer
bonding-antibonding splitting destroying it. The bilayer Fermi surface
splitting is practically zero.

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The categories of this paper are: funct-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: astro-ph
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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
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The categories of this paper are: q-bio
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
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The categories of this paper are: q-fin
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: math
0
The categories of this paper are: hep-ph
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The categories of this paper are: nucl-th