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Title: Gaps and pseudogaps in perovskite rare earth nickelates

Journal Article · · APL materials
DOI:https://doi.org/10.1063/1.4907771· OSTI ID:22415294
; ; ;  [1]; ; ; ; ; ;  [2];  [1]
  1. Department of Physics, University of California, Santa Barbara, California 93106 (United States)
  2. Materials Department, University of California, Santa Barbara, California 93106 (United States)

We report on tunneling measurements that reveal the evolution of the quasiparticle state density in two rare earth perovskite nickelates, NdNiO{sub 3} and LaNiO{sub 3}, that are close to a bandwidth controlled metal to insulator transition. We measure the opening of a sharp gap of ∼30 meV in NdNiO{sub 3} in its insulating ground state. LaNiO{sub 3}, which remains a correlated metal at all practical temperatures, exhibits a pseudogap of the same order. The results point to both types of gaps arising from a common origin, namely, a quantum critical point associated with the T = 0 K metal-insulator transition. The results support theoretical models of the quantum phase transition in terms of spin and charge instabilities of an itinerant Fermi surface.

OSTI ID:
22415294
Journal Information:
APL materials, Vol. 3, Issue 6; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2166-532X
Country of Publication:
United States
Language:
English