title: Suppression of the antiferromagnetic pseudogap in the electron-doped high-temperature superconductor by protect annealing.
abstract: In the hole-doped cuprates, a small number of carriers suppresses antiferromagnetism and induces superconductivity. In the electron-doped cuprates, on the other hand, superconductivity appears only in a narrow window of high-doped Ce concentration after reduction annealing, and strong antiferromagnetic correlation persists in the superconducting phase. Recently, Pr(1.3-x)La0.7Ce(x)CuO4 (PLCCO) bulk single crystals annealed by a protect annealing method showed a high critical temperature of around 27 K for small Ce content down to 0.05. Here, by angle-resolved photoemission spectroscopy measurements of PLCCO crystals, we observed a sharp quasi-particle peak on the entire Fermi surface without signature of an antiferromagnetic pseudogap unlike all the previous work, indicating a dramatic reduction of antiferromagnetic correlation length and/or of magnetic moments. The superconducting state was found to extend over a wide electron concentration range. The present results fundamentally challenge the long-standing picture on the electronic structure in the electron-doped regime.
authors: Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: M
authors: M
authors: Horio
authors: Department of Engineering and Applied Sciences, Sophia University, Tokyo 102-8554, Japan.
authors: T
authors: T
authors: Adachi
authors: Department of Applied Physics, Tohoku University, Sendai 980-8579, Japan.
authors: Y
authors: Y
authors: Mori
authors: Department of Applied Physics, Tohoku University, Sendai 980-8579, Japan.
authors: A
authors: A
authors: Takahashi
authors: Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: T
authors: T
authors: Yoshida
authors: Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: H
authors: H
authors: Suzuki
authors: Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: L C C
authors: LC
authors: Ambolode
authors: Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: K
authors: K
authors: Okazaki
authors: KEK, Photon Factory, Tsukuba 305-0801, Japan.
authors: K
authors: K
authors: Ono
authors: KEK, Photon Factory, Tsukuba 305-0801, Japan.
authors: H
authors: H
authors: Kumigashira
authors: Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan.
authors: H
authors: H
authors: Anzai
authors: Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan.
authors: M
authors: M
authors: Arita
authors: Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan.
authors: H
authors: H
authors: Namatame
authors: Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan.|Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
authors: M
authors: M
authors: Taniguchi
authors: Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: D
authors: D
authors: Ootsuki
authors: Graduate School of Frontier Sciences, University of Tokyo, Kashiwa 277-0882, Japan.
authors: K
authors: K
authors: Sawada
authors: Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: M
authors: M
authors: Takahashi
authors: Graduate School of Frontier Sciences, University of Tokyo, Kashiwa 277-0882, Japan.
authors: T
authors: http://orcid.org/0000-0002-7682-2348
authors: T
authors: Mizokawa
authors: Department of Applied Physics, Tohoku University, Sendai 980-8579, Japan.
authors: Y
authors: Y
authors: Koike
authors: Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: A
authors: A
authors: Fujimori