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This content will become publicly available on May 31, 2017

Title: Electron doping evolution of the neutron spin resonance in NaFe1-xCoxAs

Neutron spin resonance, a collective magnetic excitation coupled to superconductivity, is one of the most prominent features shared by a broad family of unconventional superconductors including copper oxides, iron pnictides, and heavy fermions. In this paper, we study the doping evolution of the resonances in NaFe1–xCoxAs covering the entire superconducting dome. For the underdoped compositions, two resonance modes coexist. As doping increases, the low-energy resonance gradually loses its spectral weight to the high-energy one but remains at the same energy. By contrast, in the overdoped regime we only find one single resonance, which acquires a broader width in both energy and momentum but retains approximately the same peak position even when Tc drops by nearly a half compared to optimal doping. Furthermore, these results suggest that the energy of the resonance in electron overdoped NaFe1–xCoxAs is neither simply proportional to Tc nor the superconducting gap but is controlled by the multiorbital character of the system and doped impurity scattering effect.
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [2] ;  [3] ;  [4] ;  [1] ;  [5] ;  [6]
  1. Rice Univ., Houston, TX (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  4. Rice Univ., Houston, TX (United States); Beijing Normal Univ., Beijing (China)
  5. Normal Univ., Beijing (China)
  6. National Institute of Standards and Technology, Gaithersburg, MD (United States)
Publication Date:
OSTI Identifier:
1287031
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 93; Journal Issue: 17; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY