title: Dome-shaped magnetic order competing with high-temperature superconductivity at high pressures in FeSe.
abstract: The coexistence and competition between superconductivity and electronic orders, such as spin or charge density waves, have been a central issue in high transition-temperature (Tc) superconductors. Unlike other iron-based superconductors, FeSe exhibits nematic ordering without magnetism whose relationship with its superconductivity remains unclear. Moreover, a pressure-induced fourfold increase of Tc has been reported, which poses a profound mystery. Here we report high-pressure magnetotransport measurements in FeSe up to ∼15 GPa, which uncover the dome shape of magnetic phase superseding the nematic order. Above ∼6 GPa the sudden enhancement of superconductivity (Tc≤38.3 K) accompanies a suppression of magnetic order, demonstrating their competing nature with very similar energy scales. Above the magnetic dome, we find anomalous transport properties suggesting a possible pseudogap formation, whereas linear-in-temperature resistivity is observed in the normal states of the high-Tc phase above 6 GPa. The obtained phase diagram highlights unique features of FeSe among iron-based superconductors, but bears some resemblance to that of high-Tc cuprates.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: J P
authors.initials: JP
authors.lastname: Sun
authors.affiliation: Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Matsuura
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.|School of Physical Science and Technology, Yunnan University, Kunming 650091, China.
authors.forename: G Z
authors.initials: GZ
authors.lastname: Ye
authors.affiliation: Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Mizukami
authors.affiliation: The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Shimozawa
authors.affiliation: Department of Engineering Science, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Matsubayashi
authors.affiliation: The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yamashita
authors.affiliation: Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Watashige
authors.affiliation: Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: S
authors.identifier: 0000-0002-6007-9617
authors.initials: S
authors.lastname: Kasahara
authors.affiliation: Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuda
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.|Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: J-Q
authors.initials: JQ
authors.lastname: Yan
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: B C
authors.initials: BC
authors.lastname: Sales
authors.affiliation: The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Uwatoko
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: J-G
authors.initials: JG
authors.lastname: Cheng
authors.affiliation: Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan.
authors.forename: T
authors.identifier: 0000-0001-5831-4924
authors.initials: T
authors.lastname: Shibauchi