Heavy-fermion quantum criticality and destruction of the Kondo effect in a nickel oxypnictide
2014 (English)In: Nature Materials, ISSN 1476-1122, E-ISSN 1476-4660, Vol. 13, no 8, 777-781 p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
Nature Publishing Group, 2014. Vol. 13, no 8, 777-781 p.
IdentifiersURN: urn:nbn:se:liu:diva-109586DOI: 10.1038/nmat3991ISI: 000339647800015PubMedID: 24859644OAI: oai:DiVA.org:liu-109586DiVA: diva2:739458