Accession Number:

AD1062213

Title:

Gaps and pseudogaps in perovskite rare earth nickelates

Descriptive Note:

Journal Article - Embargoed Full-Text

Corporate Author:

University of California Santa Barbara United States

Personal Author(s):

• Allen, S. J.
• Hauser,Adam J.
• Mikheev,Evgeny
• Zhang,Jack Y.
• Moreno,Nelson E.
• Son,Junwoo
• Ouellette,Daniel G.
• Kally,James
• Kozhanov,Alex
• Balents,Leon
• Stemmer,Susanne

Report Date:

2015-04-23

Pagination or Media Count:

7.0

Abstract:

We report on tunneling measurements that reveal the evolution of the quasiparticle state density in two rare earth perovskite nickelates, NdNiO3 and LaNiO3, that are close to a bandwidth controlled metal to insulator transition. We measure the opening of a sharp gap of 30 meV in NdNiO3 in its insulating ground state. LaNiO3, 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.

Descriptors:

• PEROVSKITES
• measurement
• metal insulator transitions
• phase transformations

Subject Categories:

• Geology, Geochemistry and Mineralogy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE