Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Suppression of the antiferromagnetic pseudogap in the electron-doped
  high-temperature superconductor by "protect annealing"   In the hole-doped cuprates, a small amount of carriers suppresses
antiferromagnetism and induces superconductivity. In the electron-doped
cuprates, on the other hand, superconductivity appears only in a narrow range
of high electron concentration ($\sim$ doped Ce content) after reduction
annealing, and strong antiferromagnetic (AFM) correlation persists in the
superconducting phase. Recently, Pr$_{1.3-x}$La$_{0.7}$Ce$_{x}$CuO$_{4}$
(PLCCO) bulk single crystals annealed by a "protect annealing" method showed a
high $T_c$ of $\sim$ 27 K for small Ce content down to $x \sim 0.05$. By
angle-resolved photoemission spectroscopy (ARPES) measurements of PLCCO
crystals, we observed a sharp quasi-particle peak on the entire Fermi surface
without signature of an AFM pseudogap unlike all the previous work, indicating
a dramatic reduction of AFM correlation length and/or of magnetic moments. The
superconducting state was found to extend over a wide electron concentration
range. The present ARPES results fundamentally change the long-standing picture
on the electronic structure in the electron-doped regime.

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The categories of this paper are: astro-ph
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol