April 2014

Journal

Magnetic phase diagram of a five-orbital Hubbard model in the real-space Hartree-Fock approximation varying the electronic density

By:
Luo, Qinlong ; Dagotto Mir, Elbio R
Journal Name:
Physical Review B
Page Number:
45115
Volume:
89
Issue Number:
4
Publication Date:
April 3, 2014
View DOI Listing:
https://doi.org/10.1103/PhysRevB.89.045115

Abstract

Usingthereal-spaceHartree-Fockapproximation,themagneticphasediagramofafive-orbitalHubbardmodelfortheiron-basedsuperconductorsisstudiedvaryingtheelectronicdensitynintherangefromfivetosevenelectronspertransitionmetalatom.TheHubbardinteractionUisalsovaried,atafixedHundcouplingJ/U=0.25.Severalqualitativetrendsandavarietyofcompetingmagneticstatesareobserved.Atn=5,arobustG-typeantiferromagneticinsulatorisfound,inagreementwithexperimentalresultsforBaMn2As2.Asnincreasesawayfrom5,magneticstateswithanincreasingnumberofnearest-neighborsferromagneticlinksbecomeenergeticallystable.Thisincludesthewell-knownC-typeantiferromagneticstateatn=6,theE-phaseknowntoexistinFeTe,andalsoavarietyofnovelstatesnotfoundyetexperimentally,someoftheminvolvingblocksofferromagneticallyorientedspins.Regionsofphaseseparation,asinMnoxides,havealsobeendetected.Comparisontoprevioustheoreticalinvestigationsindicatethatthesequalitativetrendsmaybegenericcharacteristicsofphasediagramsofmulti-orbitalHubbardmodels.


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