Please use this identifier to cite or link to this item: http://hdl.handle.net/10995/111239
Title: Effect of Correlations and Doping on the Spin Susceptibility of Iron Pnictides: the Case of KFe2As2
Authors: Skornyakov, S. L.
Anisimov, V. I.
Vollhardt, D.
Issue Date: 2014
Publisher: Izdatel'stvo Nauka
Pleiades Publishing Ltd
Citation: Skornyakov S. L. Effect of Correlations and Doping on the Spin Susceptibility of Iron Pnictides: the Case of KFe2As2 / S. L. Skornyakov, V. I. Anisimov, D. Vollhardt. — DOI 10.3390/su132313019 // JETP Letters. — 2014. — Vol. 100. — Iss. 2. — P. 120-125.
Abstract: The temperature dependence of the paramagnetic susceptibility of the iron pnictide superconductor KFe2As2 and its connection with the spectral properties of that material is investigated by a combination of density functional theory (DFT) in the local density approximation and dynamical mean-field theory (DMFT). Unlike other iron pnictide parent compounds where the typical oxidation state of iron is 2, the formal valence of Fe in KFe2As2 is 2.5, corresponding to an effective doping with 0.5 hole per iron atom compared to, for example, BaFe2As2. This shifts the chemical potential and thereby reduces the distance between the peaks in the spectral functions of KFe2As2 and the Fermi energy as compared to BaFe2As2. The shift, which is clearly seen on the level of DFT as well as in DMFT, is further enhanced by the strong electronic correlations in KFe2As2. In BaFe2As2 the presence of these peaks results (Phys. Rev. B 86, 125124 (2012)) in a temperature increase in the susceptibility up to a maximum at ∼1000 K. While the temperature increase was observed experimentally the decrease at even higher temperatures is outside the range of experimental observability. We show that in KFe2As2 the situation is different. Namely, the reduction of the distance between the peaks and the Fermi level due to doping shifts the maximum in the susceptibility to much lower temperatures, such that the decrease in the susceptibility becomes visible in experiment. © 2014, Pleiades Publishing, Inc.
URI: http://hdl.handle.net/10995/111239
Access: info:eu-repo/semantics/openAccess
SCOPUS ID: 84908108714
PURE ID: 403253
ISSN: 0021-3640
DOI: 10.3390/su132313019
metadata.dc.description.sponsorship: This work was supported by the Russian Foundation for Basic Research (project nos. 13-02-00050 a and 13-03-00641 a), by the Presidium of the Ural Branch, Russian Academy of Sciences (project nos. 14 2 NP 164 and 12 P2 1017), and in part by Deutsche Forschungsgemeinschaft (Transregio TRR 80). The work of S.L.S. was supported by the Dynasty Foundation. S.L.S and V.I.A. are grateful to the Center for Electronic Correlations and Magnetism, University of Augsburg for hospitality. All results reported here were obtained using the “Uran” supercomputer, Institute of Metal Physics, Ural Branch, Russian Academy of Sciences.
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