title: Pressure-driven quantum criticality in iron-selenide superconductors.
abstract: We report a finding of a pressure-induced quantum critical transition in K0.8Fe(x)Se2 (x = 1.7 and 1.78) superconductors through in situ high-pressure electrical transport and x-ray diffraction measurements in diamond anvil cells. Transitions from metallic Fermi liquid behavior to non-Fermi liquid behavior and from antiferromagnetism to paramagnetism are found in the pressure range of 9.2-10.3 GPa, in which superconductivity tends to disappear. The change around the quantum critical point from the coexisting antiferromagnetism state and the Fermi liquid behavior to the paramagnetism state and the non-Fermi liquid behavior in the iron-selenide superconductors demonstrates a unique mechanism for their quantum critical transition.
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Guo
authors.forename: Xiao-Jia
authors.initials: XJ
authors.lastname: Chen
authors.forename: Jianhui
authors.initials: J
authors.lastname: Dai
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.forename: Jiangang
authors.initials: J
authors.lastname: Guo
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Chen
authors.forename: Qi
authors.initials: Q
authors.lastname: Wu
authors.forename: Dachun
authors.initials: D
authors.lastname: Gu
authors.forename: Peiwen
authors.initials: P
authors.lastname: Gao
authors.forename: Lihong
authors.initials: L
authors.lastname: Yang
authors.forename: Ke
authors.initials: K
authors.lastname: Yang
authors.forename: Xi
authors.initials: X
authors.lastname: Dai
authors.forename: Ho-kwang
authors.initials: HK
authors.lastname: Mao
authors.forename: Liling
authors.initials: L
authors.lastname: Sun
authors.forename: Zhongxian
authors.initials: Z
authors.lastname: Zhao