Nonlocal correlations in iron pnictides and chalcogenides
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Nonlocal correlations in iron pnictides and chalcogenides. / Bhattacharyya, Shinibali; Bjornson, Kristofer; Zantout, Karim; Steffensen, Daniel; Fanfarillo, Laura; Kreisel, Andreas; Valent, Roser; Andersen, Brian M.; Hirschfeld, P. J.
In: Physical Review B, Vol. 102, No. 3, 035109, 06.07.2020.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Nonlocal correlations in iron pnictides and chalcogenides
AU - Bhattacharyya, Shinibali
AU - Bjornson, Kristofer
AU - Zantout, Karim
AU - Steffensen, Daniel
AU - Fanfarillo, Laura
AU - Kreisel, Andreas
AU - Valent, Roser
AU - Andersen, Brian M.
AU - Hirschfeld, P. J.
PY - 2020/7/6
Y1 - 2020/7/6
N2 - Deviations of low-energy electronic structurse of iron-based superconductors from density-functional-theory predictions have been parametrized in terms of band- and orbital-dependent mass renormalizations and energy shifts. The former have typically been described in terms of a local self-energy within the framework of dynamical mean field theory, while the latter appears to require nonlocal effects due to interband scattering. By calculating the renormalized band structure in both random phase approximation (RPA) and the two-particle self-consistent approximation (TPSC), we show that correlations in pnictide systems like LaFeAsO and LiFeAs can be described rather well by a nonlocal self-energy. In particular, Fermi pocket shrinkage as seen in experiments occurs due to repulsive interband finite-energy scattering. For the canonical iron chalcogenide system FeSe in its bulk tetragonal phase, the situation is, however, more complex since even including momentum-dependent band renormalizations cannot explain experimental findings. We propose that the nearest-neighbor Coulomb interaction may play an important role in band-structure renormalization in FeSe. We further compare our evaluations of nonlocal quasiparticle scattering lifetime within RPA and TPSC with experimental data for LiFeAs.
AB - Deviations of low-energy electronic structurse of iron-based superconductors from density-functional-theory predictions have been parametrized in terms of band- and orbital-dependent mass renormalizations and energy shifts. The former have typically been described in terms of a local self-energy within the framework of dynamical mean field theory, while the latter appears to require nonlocal effects due to interband scattering. By calculating the renormalized band structure in both random phase approximation (RPA) and the two-particle self-consistent approximation (TPSC), we show that correlations in pnictide systems like LaFeAsO and LiFeAs can be described rather well by a nonlocal self-energy. In particular, Fermi pocket shrinkage as seen in experiments occurs due to repulsive interband finite-energy scattering. For the canonical iron chalcogenide system FeSe in its bulk tetragonal phase, the situation is, however, more complex since even including momentum-dependent band renormalizations cannot explain experimental findings. We propose that the nearest-neighbor Coulomb interaction may play an important role in band-structure renormalization in FeSe. We further compare our evaluations of nonlocal quasiparticle scattering lifetime within RPA and TPSC with experimental data for LiFeAs.
U2 - 10.1103/PhysRevB.102.035109
DO - 10.1103/PhysRevB.102.035109
M3 - Journal article
VL - 102
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 3
M1 - 035109
ER -
ID: 247158601