Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Temperature and Spatial Dependence of the Superconducting and Pseudogap
  of NdFeAsO0.86F0.14   The discovery of superconductivity with a critical temperature exceeding 55 K
in the iron-oxypnictides and related compounds has quite suddenly given the
community a new set of materials - breaking the tyranny of copper. This new
class of materials raises fundamental questions related to the origin of the
electron pairing in the superconducting state and to the similarity to
superconductivity in the cuprates. Here, we report spatially resolved
measurements using scanning tunneling microscopy/spectroscopy (STM/STS) of the
newly discovered iron-based layered superconductor NdFeAsO0.86F0.14 (Tc = 48 K)
as a function of temperature. The tunneling spectra at 17 K show a suppression
of spectral intensity within +/- 10 meV, indicative of the opening of the
superconducting gap (SG). Below Tc, the sample exhibits two characteristic gaps
- a large one (18 meV) and a small one (9 meV) - existing in different spatial
locations. Both gaps are closed above Tc at the bulk Tc, but only the small gap
can be fitted with a superconducting gap function. This gap displays a BCS -
like order parameter. Above Tc, at the same location where the small gap was
observed, a pseudogap (PG) opens abruptly at a temperature just above Tc and
closes at 120 K. In contrast to the cuprates, the SG and PG have competing
order parameters.

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The categories of this paper are: patt-sol
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ex
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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: math
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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
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The categories of this paper are: supr-con
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The categories of this paper are: hep-th
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-th
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The categories of this paper are: stat