July 2016

Journal

Orbital-selective Mott phases of a one-dimensional three-orbital Hubbard model studied using computational techniques

By:
Liu, Guangkun; Kaushal, Nitin ; Liu, Shaozhi; Bishop, Christopher; Wang, Yan; Johnston, Steve; Alvarez, Gonzalo ; Moreo, Adriana ; Dagotto Mir, Elbio R
Journal Name:
Physical Review E
Page Number:
963313
Volume:
93
Issue Number:
6
Publication Date:
July 19, 2016
View DOI Listing:
https://doi.org/10.1103/PhysRevE.93.063313

Abstract

Arecentlyintroducedone-dimensionalthree-orbitalHubbardmodeldisplaysorbital-selectiveMottphaseswithexoticspinarrangementssuchasspinblockstates[J.Rinc´onetal.,Phys.Rev.Lett.112,106405(2014)].Inthispublicationweshowthattheconstrained-pathquantumMonteCarlo(CPQMC)techniquecanaccuratelyreproducethephasediagramofthismultiorbitalone-dimensionalmodel,pavingthewaytofutureCPQMCstudiesinsystemswithmorechallenginggeometries,suchasladdersandplanes.ThesuccessofthisapproachreliesonusingtheHartree-FocktechniquetopreparethetrialstatesneededinCPQMC.Wealsostudyasimplifiedversionofthemodelwherethepair-hoppingtermisneglectedandtheHundcouplingisrestrictedtoitsIsingcomponent.Thecorrespondingphasediagramsareshowntobeonlymildlyaectedbytheabsenceofthesetechnicallydiÿcult-to-implementterms.ThisisconfirmedbyadditionalDensityMatrixRenormalizationGroupandDeterminantQuantumMonteCarlocalculationscarriedoutforthesamesimplifiedmodel,withthelatterdisplayingonlymildFermionsignproblems.Weconcludethatthesemethodsareabletocapturequantitativelytherichphysicsoftheseveralorbital-selectiveMottphases(OSMP)displayedbythismodel,thusenablingcomputationalstudiesoftheOSMPregimeinhigherdimensions,beyondstaticordynamicmeanfieldapproximations.