title: Slater to Mott Crossover in the Metal to Insulator Transition of Nd_{2}Ir_{2}O_{7}.
abstract: We present an angle-resolved photoemission study of the electronic structure of the three-dimensional pyrochlore iridate Nd_{2}Ir_{2}O_{7} through its magnetic metal-insulator transition. Our data reveal that metallic Nd_{2}Ir_{2}O_{7} has a quadratic band, touching the Fermi level at the Γ point, similar to that of Pr_{2}Ir_{2}O_{7}. The Fermi node state is, therefore, a common feature of the metallic phase of the pyrochlore iridates. Upon cooling below the transition temperature, this compound exhibits a gap opening with an energy shift of quasiparticle peaks like a band gap insulator. The quasiparticle peaks are strongly suppressed, however, with further decrease of temperature, and eventually vanish at the lowest temperature, leaving a nondispersive flat band lacking long-lived electrons. We thereby identify a remarkable crossover from Slater to Mott insulators with decreasing temperature. These observations explain the puzzling absence of Weyl points in this material, despite its proximity to the zero temperature metal-insulator transition.
authors: ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors: M
authors: M
authors: Nakayama
authors: ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors: Takeshi
authors: T
authors: Kondo
authors: ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors: Z
authors: Z
authors: Tian
authors: ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors: J J
authors: JJ
authors: Ishikawa
authors: ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors: M
authors: M
authors: Halim
authors: ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors: C
authors: C
authors: Bareille
authors: ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.|Physics Department, Faculty of Science, Beirut Arab University, Beirut 11-5020, Lebanon.
authors: W
authors: W
authors: Malaeb
authors: ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors: K
authors: K
authors: Kuroda
authors: ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors: T
authors: T
authors: Tomita
authors: UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan.
authors: S
authors: S
authors: Ideta
authors: UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan.
authors: K
authors: K
authors: Tanaka
authors: Toyota Technological Institute, Nagoya 468-8511, Japan.
authors: M
authors: M
authors: Matsunami
authors: Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan.
authors: S
authors: S
authors: Kimura
authors: Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan.
authors: N
authors: N
authors: Inami
authors: Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan.
authors: K
authors: K
authors: Ono
authors: Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan.
authors: H
authors: H
authors: Kumigashira
authors: Kavli Institute for Theoretical Physics, Santa Barbara, California 93106, USA.
authors: L
authors: L
authors: Balents
authors: ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.|CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan.
authors: S
authors: S
authors: Nakatsuji
authors: ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors: S
authors: S
authors: Shin