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Title: Nonrigid band shift and nonmonotonic electronic structure changes upon doping in the normal state of the pnictide high-temperature superconductor Ba ( F e 1 - x C o x ) 2 A s 2

Here, we report systematic angle-resolved photoemission (ARPES) experiments using different photon polarizations and experimental geometries and find that the doping evolution of the normal state of Ba(Fe 1–xCo x) 2As 2 deviates significantly from the predictions of a rigid band model. The data reveal a nonmonotonic dependence upon doping of key quantities such as band filling, bandwidth of the electron pocket, and quasiparticle coherence. Our analysis suggests that the observed phenomenology and the inapplicability of the rigid band model in Co-doped Ba122 are due to electronic correlations, and not to the either the strength of the impurity potential, or self-energy effects due to impurity scattering. Our findings indicate that the effects of doping in pnictides are much more complicated than currently believed. More generally, they indicate that a deep understanding of the evolution of the electronic properties of the normal state, which requires an understanding of the doping process, remains elusive even for the 122 iron-pnictides, which are viewed as the least correlated of the high-T C unconventional superconductors.
 [1] ;  [2] ;  [2] ;  [3] ;  [3] ;  [3] ;  [4] ;  [5] ;  [6] ;  [1] ;  [7]
  1. Univ. of Tennessee, Knoxville, TN (United States)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  5. Univ. of Missouri, Columbia, MO (United States)
  6. Brookhaven National Lab. (BNL), Upton, NY (United States); State Univ. of New York, Stony Brook, NY (United States)
  7. Univ. of Tennessee, Knoxville, TN (United States); Shanghai Jiao Tong Univ., Shanghai (China)
Publication Date:
Grant/Contract Number:
AC05-00OR22725; AC02-05CH11231
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 94; Journal Issue: 19; Journal ID: ISSN 2469-9950
American Physical Society (APS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1333605; OSTI ID: 1398443