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Title: Gaps and pseudogaps in perovskite rare earth nickelates

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.
Authors:
; ; ;  [1] ; ; ; ; ; ;  [2] ;  [1] ;  [3]
  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)
  3. (United States)
Publication Date:
OSTI Identifier:
22415294
Resource Type:
Journal Article
Resource Relation:
Journal Name: APL materials; Journal Volume: 3; Journal Issue: 6; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; DENSITY; ENERGY GAP; FERMI LEVEL; GROUND STATES; LANTHANUM COMPOUNDS; NEODYMIUM COMPOUNDS; NICKELATES; PEROVSKITE; PHASE TRANSFORMATIONS; SPIN; TUNNEL EFFECT