Doping Dependence of Correlation Effects in K{1-x}Fe{2-y}Se2 Superconductor: LDA'+DMFT Investigation

Abstract

We present detailed LDA'+DMFT investigation of doping dependence of correlation effects in novel K{1-x}Fe{2-y}Se2 superconductor. Calculations were performed at four different hole doping levels, starting from hypothetical stoichiometric composition with total number of electrons equal to 29 per unit cell through 28 and 27.2 electrons towards the case of 26.52, which corresponds to chemical composition K{0.76}Fe{1.72}Se2 studied in recent ARPES experiments. In general case the increase of hole doping leads to quasiparticle bands in wide energy window +/-2 eV around the Fermi level becoming more broadened by lifetime effects, while correlation induced compression of Fe-3d LDA' bandwidths stays almost the same and of the order of ~1.3 for all hole concentrations. However close to the Fermi level situation is more complicated. Here in the energy interval from -1.0 eV to 0.4 eV the bare Fe-3d LDA' bands are compressed by significantly larger renormalization factors up to 5 with hole doping increase, while the value of Coulomb interaction remains the same. This fact manifests the increase of correlation effects with hole doping in K{1-x}Fe{2-y}Se2 system. Moreover in contrast to typical pnictides K{1-x}Fe{2-y}Se2 does not have well defined quasiparticle bands on the Fermi leves but pseudogap like "dark" region instead. We also find that with the growth of hole doping Fe-3d orbitals of various symmetries are affected by correlations in a different way in different parts of Brillouin zone. To illustrate this we determine quasiparticle mass renormalization factors and energy shifts, which transform the bare Fe-3d LDA' bands of various symmetries into LDA'+DMFT quasiparticle bands. These renormalization factors effectively mimic more complicated energy dependent self-energy effects and can be used to analyze the available ARPES data.

9 pages, 4 figures, 1 table

References in corpus (23)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Density functional study of FeS, FeSe and FeTe: Electronic structure, magnetism, phonons and superconductivity
• Superconductivity up to 37 K in (A1-xSrx)Fe2As2 with A=K and Cs
• To What Extent Iron-Pnictide New Superconductors Have Been Clarified: A Progress Report
• Correlated electronic structure of LaOFeAs
• Heavily electron-doped electronic structure and isotropic superconducting gap in AxFe2Se2 (A=K,Cs)
• Anisotropic thermodynamic and transport properties of single crystalline (Ba${}_{1-x}$K${}_x$)Fe${}_2$As${}_2$ (x = 0 and 0.45)
• A review of Fe-chalcogenide superconductors: the simplest Fe-based superconductor
• High - Temperature Superconductivity in Iron Based Layered Compounds
• Iron based superconductors: magnetism, superconductivity and electronic structure
• Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in A${}_x$Fe${}_{2-y}$Se${}_2$ (A=K, Rb) Superconductors
• Magnetic and structural transitions in layered FeAs systems: AFe2As2 versus RFeAsO compounds
• Electronic Structure of Prototype AFe_2As_2 and ReOFeAs High-Temperature Superconductors: a Comparison
• KFe_2Se_2 is the parent compound of K-doped iron selenide superconductors
• Coulomb repulsion and correlation strength in LaFeAsO from Density Functional and Dynamical Mean-Field Theories
• Classification of the electronic correlation strength in the Fe-pnictides: The case of the parent compound BaFe2As2
• Normal State Correlated Electronic Structure of Iron Pnictides
• Electronic structure of oxygen-free 38K superconductor Ba1-xKxFe2As2 in comparison with BaFe2As2 from first principles
• Electronic Structure, Topological Phase Transitions and Superconductivity in (K,Cs)xFe2Se2
• Coulomb correlation effects in LaOFeAs: LDA+DMFT(QMC) study
• Overview on the physics and materials of the new superconductor KxFe2-ySe2
• Consistent LDA'+DMFT -- an unambiguous way to avoid double counting problem: NiO test
• LDA'+DMFT Investigation of Electronic Structure of K{1-x}Fe{2-y}Se2 Superconductor

Cited by in corpus (6)

• Electronic structure of FeSe monolayer superconductors
• Electronic structure of FeSe monolayer superconductors: shallow bands and correlations
• Electronic structure of NaFeAs superconductor: LDA+DMFT calculations compared with ARPES experiment
• Electronic structure of iron-based superconductors: from pnictides to chalcogenides and other similar systems
• On the origin of the shallow and "replica" bands in FeSe monolayer superconductors
• Hidden Fermi surface in K${}_x$Fe${}_{2-y}$Se${}_2$: LDA+DMFT study