Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fermi pockets and correlation effects in underdoped YBa2Cu3O6.5   The detection of quantum oscillations in the electrical resistivity of
YBa2Cu3O6.5 provides direct evidence for the existence of Fermi surface pockets
in an underdoped cuprate. We present a theoretical study of the electronic
structure of YBa2Cu3O7-d (YBCO) aiming at establishing the nature of these
Fermi pockets, i.e. CuO2 plane versus CuO chain or BaO. We argue that electron
correlation effects, such as orbital-dependent band distortions and highly
anisotropic self-energy corrections, must be taken into account in order to
properly interpret the quantum oscillation experiments.

2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th