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|Title:||Exchange interactions and sensitivity of the Ni two-hole spin state to Hund's coupling in doped NdNiO2|
Savrasov, S. Y.
|Publisher:||American Physical Society|
|Citation:||Exchange interactions and sensitivity of the Ni two-hole spin state to Hund's coupling in doped NdNiO2 / X. Wan, V. Ivanov, G. Resta, et al. — DOI 10.1103/PhysRevB.103.075123 // Physical Review B. — 2021. — Vol. 103. — Iss. 7. — 075123.|
|Abstract:||Using the density-functional-based LDA+U method and linear-response theory, we study the magnetic exchange interactions of the superconductor Nd1-xSrxNiO2. Our calculated nearest-neighbor exchange constant J1=82 meV is large, weakly affected by doping, and is only slightly smaller than that found in the sister compound CaCuO2. However, we find that the hole doping significantly enhances the interlayer exchange coupling as it affects the magnetic moment of the Ni-3d3z2-r2 orbital. This can be understood in terms of the small hybridization of Ni-3d3z2-r2 within the NiO2 plane, which results in a flat band near the Fermi level, and its large overlap along the z direction. We also demonstrate that the Nd-5d states appearing at the Fermi level do not affect the magnetic exchange interactions, and thus they may not participate in the superconductivity of this compound. Whereas many previous works emphasized the importance of the Ni-3dx2-y2 and Nd-5d orbitals, we analyze instead the solution of the Ni-3dx2-y2/Ni-3d3z2-r2 minimal model using dynamical mean field theory. It reveals an underlying Mott insulating state that, depending on the precise values of the intra-atomic Hund's coupling smaller or larger than 0.83 eV, selects upon doping either S=0 or 1 two-hole states at low energies, leading to very different quasiparticle band structures. We propose that trends upon doping in the spin excitation spectrum and the quasiparticle density of states can be a way to probe the Ni 3d8 configuration. © 2021 American Physical Society.|
MEAN FIELD THEORY
DYNAMICAL MEAN-FIELD THEORY
INTERLAYER EXCHANGE COUPLING
MAGNETIC EXCHANGE INTERACTIONS
QUASIPARTICLE BAND STRUCTURES
|metadata.dc.description.sponsorship:||X.W. is supported by the NSFC (Grants No. 11834006, No. 11525417, No. 51721001, and No. 11790311), National Key R&D Program of China (Grants No. 2018YFA0305704 and No. 2017YFA0303203), and by 111 Project. X.W. also acknowledges the support from the Tencent Foundation through the XPLORER PRIZE. V.I., G.R., and S.Y.S. are supported by NSF DMR Grant No. 1832728. I.L. acknowledges support by the Russian Foundation for Basic Research (Project No. 18-32-20076). The DMFT electronic structure calculations were supported by the state assignment of Minobrnauki of Russia (theme “Electron” No. AAAA-A18-118020190098-5).|
|Appears in Collections:||Научные публикации, проиндексированные в SCOPUS и WoS CC|
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