TY - JOUR

T1 - Coulomb correlations in a germanide iron-based superconductor: The example of YFe2Ge2

AU - Skornyakov, S. l.

AU - Anisimov, V. i.

N1 - The DFT structural optimization and electronic structure calculations were carried out within the state assignment of Ministry of Science and Higher Education of the Russian Federation (theme “Electron” No. 122021000039-4). The calculations including the analysis of the lattice, spectral and magnetic properties were supported by the Russian Science Foundation (Project No. 19-12-00012).

PY - 2023

Y1 - 2023

N2 - We report results of a detailed theoretical study of the effect of Coulomb correlations on the structural, electronic, and magnetic properties of the non-pnictide iron-based superconductor YFe2Ge2. In particular, by employing the density functional theory plus dynamical mean-field theory method (DFT+DMFT) we perform a structural optimization of the unit-cell volume and the internal coordinate zGe of Ge. Our results for the lattice parameters obtained by DFT+DMFT show a much better agreement with experiment as compared to those calculated by DFT implying the importance of correlation effects. We show that YFe2Ge2 is a moderately correlated system with electron-electron correlations being strong enough to renormalize the low-energy band structure but not sufficient to form Hubbard bands, in close analogy to the iron-based pnictides and chalcogenides. The analysis of the local spin-spin correlation function and momentum-dependent spin susceptibility χ(q) indicates the correlation induced formation of short-lived local moments in the Fe t2g states and the presence of competing spin fluctuations, in agreement with experiment.

AB - We report results of a detailed theoretical study of the effect of Coulomb correlations on the structural, electronic, and magnetic properties of the non-pnictide iron-based superconductor YFe2Ge2. In particular, by employing the density functional theory plus dynamical mean-field theory method (DFT+DMFT) we perform a structural optimization of the unit-cell volume and the internal coordinate zGe of Ge. Our results for the lattice parameters obtained by DFT+DMFT show a much better agreement with experiment as compared to those calculated by DFT implying the importance of correlation effects. We show that YFe2Ge2 is a moderately correlated system with electron-electron correlations being strong enough to renormalize the low-energy band structure but not sufficient to form Hubbard bands, in close analogy to the iron-based pnictides and chalcogenides. The analysis of the local spin-spin correlation function and momentum-dependent spin susceptibility χ(q) indicates the correlation induced formation of short-lived local moments in the Fe t2g states and the presence of competing spin fluctuations, in agreement with experiment.

UR - http://www.scopus.com/inward/record.url?partnerID=8YFLogxK&scp=85163337438

UR - https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=tsmetrics&SrcApp=tsm_test&DestApp=WOS_CPL&DestLinkType=FullRecord&KeyUT=001010108100001

U2 - 10.1103/PhysRevB.107.235103

DO - 10.1103/PhysRevB.107.235103

M3 - Article

VL - 107

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 23

M1 - 235103

ER -