Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electric field-induced oxygen vacancies in YBa2Cu3O7   The microscopic doping mechanism behind the superconductor-to-insulator
transition of a thin film of YBa2Cu3O7 was recently identified as due to the
migration of O atoms from the CuO chains of the film. Here we employ
density-functional theory calculations to study the evolution of the electronic
structure of a slab of YBa2 Cu3 O7 in presence of oxygen vacancies under the
influence of an external electric field. We find that under massive electric
fields isolated O atoms are pulled out of the surface consisting of CuO chains.
As vacancies accumulate at the surface, a configuration with vacancies located
in the chains inside the slab becomes energetically preferred thus providing a
driving force for O migration towards the surface. Regardless of the defect
configuration studied, the electric field is always fully screened near the
surface thus negligibly affecting diffusion barriers across the film.

7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys