October 2014

Journal

Magnetic states of the five-orbital Hubbard model for one-dimensional iron-based superconductors

By:
Luo, Qinlong ; Foyevtsova, Kateryna ; Samolyuk, German D; Reboredo, Fernando A; Dagotto, G
Journal Name:
Physical Review B
Page Number:
35128
Volume:
90
Issue Number:
3
Publication Date:
October 1, 2014
View DOI Listing:
https://doi.org/10.1103/PhysRevB.90.035128

Abstract

Themagneticphasediagramsofmodelsforquasi-one-dimensionalcompoundsbelongingtotheiron-based-superconductorfamilyarepresented.Thefive-orbitalHubbardmodelandthereal-spaceHartree–Fockapproximationareemployed,supplementedbydensityfunctionaltheorytoobtainthehoppingamplitudes.PhasediagramsareconstructedbyvaryingtheHubbardUandHundJcouplingsatzerotemperature.Thestudyiscarriedoutatelectronicdensity(electronsperiron)n=5.0,whichisofrelevanceforthealready-knownmaterialTlFeSe2,andalsoatn=6.0,whererepresentativecompoundsstillneedtobesynthesized.Atn=5.0thereisacleardominanceofstaggeredspinorderalongthechaindirection.Atn=6.0andwiththerealisticHundcouplingJ/U=0.25,thephasediagramisfarricher,includingavarietyof“block”statesinvolvingferromagneticclustersthatareantiferromagneticallycoupled,inqualitativeagreementwithrecentdensitymatrixrenormalizationgroupcalculationsforthethree-orbitalHubbardmodelinadifferentcontext.Theseblockstatesarisefromthecompetitionbetweenferromagneticorder(inducedbydoubleexchangeandprevailingatlargeJ/U)andantiferromagneticorder(dominatingatsmallJ/U).Thedensityofstatesandorbitalcompositionsofthemanyphasesarealsoprovided.