Browsing by Author "Li, Yuke"

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    Heavy-fermion quantum criticality and destruction of the Kondo effect in a nickelﾠoxypnictide
    (Nature Publishing Group, 2014) Luo, Yongkang; Pourovskii, Leonid; Rowley, S.E.; Li, Yuke; Feng, Chunmu; Georges, Antoine; Dai, Jianhui; Cao, Guanghan; Xu, Zhuﾒan; Si, Qimiao; Ong, N.P.
    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 [1,2]. 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 [3,4]. 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.