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Title: Unconventional Fermi surface in an insulating state

Insulators occur in more than one guise; a recent finding was a class of topological insulators, which host a conducting surface juxtaposed with an insulating bulk. Here, we report the observation of an unusual insulating state with an electrically insulating bulk that simultaneously yields bulk quantum oscillations with characteristics of an unconventional Fermi liquid. We present quantum oscillation measurements of magnetic torque in high-purity single crystals of the Kondo insulator SmB6, which reveal quantum oscillation frequencies characteristic of a large three-dimensional conduction electron Fermi surface similar to the metallic rare earth hexaborides such as PrB6 and LaB6. As a result, the quantum oscillation amplitude strongly increases at low temperatures, appearing strikingly at variance with conventional metallic behavior.
Authors:
 [1] ;  [2] ;  [2] ;  [3] ;  [4] ;  [1] ;  [2] ;  [2] ;  [2] ;  [5] ;  [3] ;  [3] ;  [3] ;  [2] ;  [4] ;  [2]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Cambridge Univ., Cambridge (United Kingdom)
  3. National High Magnetic Field Lab., Tallahassee, FL (United States)
  4. Univ. of Warwick, Coventry (United Kingdom)
  5. Center for Computational Materials Science, Washington, DC (United States)
Publication Date:
OSTI Identifier:
1186042
Report Number(s):
LA-UR--15-24709
Journal ID: ISSN 0036-8075
DOE Contract Number:
AC52-06NA25396
Resource Type:
Journal Article
Resource Relation:
Journal Name: Science; Journal Volume: 349; Journal Issue: 6245
Publisher:
AAAS
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY high magnetic field science