title: Heavy-fermion quantum criticality and destruction of the Kondo effect in a nickel oxypnictide.
abstract: A quantum critical point arises at a continuous transformation between distinct phases of matter at zero temperature. Studies in antiferromagnetic heavy-fermion materials have revealed that quantum criticality has several classes, with an unconventional type that involves a critical destruction of the Kondo entanglement. To understand such varieties, it is important to extend the materials basis beyond the usual setting of intermetallic compounds. Here we show that a nickel oxypnictide, CeNiAsO, exhibits a heavy-fermion antiferromagnetic quantum critical point as a function of either pressure or P/As substitution. At the quantum critical point, non-Fermi-liquid behaviour appears, which is accompanied by a divergent effective carrier mass. Across the quantum critical point, the low-temperature Hall coefficient undergoes a rapid sign change, suggesting a sudden jump of the Fermi surface and a destruction of the Kondo effect. Our results imply that the enormous materials basis for the oxypnictides, which has been so crucial in the search for high-temperature superconductivity, will also play a vital role in the effort to establish the universality classes of quantum criticality in strongly correlated electron systems.
authors.affiliation: 1] Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China [2] Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Yongkang
authors.initials: Y
authors.lastname: Luo
authors.affiliation: 1] Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France [2] Swedish e-science Research Centre (SeRC), Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping 58183, Sweden.
authors.forename: Leonid
authors.initials: L
authors.lastname: Pourovskii
authors.affiliation: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Rowley
authors.affiliation: Department of Physics, Hangzhou Normal University, Hangzhou 310036, China.
authors.forename: Yuke
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China.
authors.forename: Chunmu
authors.initials: C
authors.lastname: Feng
authors.affiliation: Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Georges
authors.affiliation: Department of Physics, Hangzhou Normal University, Hangzhou 310036, China.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Dai
authors.affiliation: Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China.
authors.forename: Guanghan
authors.initials: G
authors.lastname: Cao
authors.affiliation: Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China.
authors.forename: Zhu'an
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA.
authors.forename: Qimiao
authors.initials: Q
authors.lastname: Si
authors.affiliation: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: N P
authors.initials: NP
authors.lastname: Ong