Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fermi surface reconstruction in electron-doped cuprates without
  antiferromagnetic long-range order   Fermi surface (FS) topology is a fundamental property of metals and
superconductors. In electron-doped cuprate Nd2-xCexCuO4 (NCCO), an unexpected
FS reconstruction has been observed in optimal- and over-doped regime
(x=0.15-0.17) by quantum oscillation measurements (QOM). This is all the more
puzzling because neutron scattering suggests that the antiferromagnetic (AFM)
long-range order, which is believed to reconstruct the FS, vanishes before
x=0.14. To reconcile the conflict, a widely discussed external magnetic
field-induced AFM long-range order in QOM explains the FS reconstruction as an
extrinsic property. Here, we report angle-resolved photoemission (ARPES)
evidence of FS reconstruction in optimal- and over-doped NCCO. The observed FSs
are in quantitative agreement with QOM, suggesting an intrinsic FS
reconstruction without field. This reconstructed FS, despite its importance as
a basis to understand electron-doped cuprates, cannot be explained under the
traditional scheme. Furthermore, the energy gap of the reconstruction decreases
rapidly near x=0.17 like an order parameter, echoing the quantum critical
doping in transport. The totality of the data points to a mysterious order
between x=0.14 and 0.17, whose appearance favors the FS reconstruction and
disappearance defines the quantum critical doping. A recent topological
proposal provides an ansatz for its origin.

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The categories of this paper are: econ
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
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The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
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The categories of this paper are: supr-con
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The categories of this paper are: adap-org
3
The categories of this paper are: physics