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dc.contributor.authorKumar, Manoranjan
dc.contributor.authorParvej, Aslam
dc.contributor.authorThomas, Simil
dc.contributor.authorRamasesha, S.
dc.contributor.authorSoos, Z. G.
dc.date.accessioned2016-03-15T14:03:34Z
dc.date.available2016-03-15T14:03:34Z
dc.date.issued2016-02-03
dc.identifier.citationEfficient density matrix renormalization group algorithm to study Y junctions with integer and half-integer spin 2016, 93 (7) Physical Review B
dc.identifier.issn2469-9950
dc.identifier.issn2469-9969
dc.identifier.doi10.1103/PhysRevB.93.075107
dc.identifier.urihttp://hdl.handle.net/10754/601364
dc.description.abstractAn efficient density matrix renormalization group (DMRG) algorithm is presented and applied to Y junctions, systems with three arms of n sites that meet at a central site. The accuracy is comparable to DMRG of chains. As in chains, new sites are always bonded to the most recently added sites and the superblock Hamiltonian contains only new or once renormalized operators. Junctions of up to N=3n+1≈500 sites are studied with antiferromagnetic (AF) Heisenberg exchange J between nearest-neighbor spins S or electron transfer t between nearest neighbors in half-filled Hubbard models. Exchange or electron transfer is exclusively between sites in two sublattices with NA≠NB. The ground state (GS) and spin densities ρr=⟨Szr⟩ at site r are quite different for junctions with S=1/2, 1, 3/2, and 2. The GS has finite total spin SG=2S(S) for even (odd) N and for MG=SG in the SG spin manifold, ρr>0(<0) at sites of the larger (smaller) sublattice. S=1/2 junctions have delocalized states and decreasing spin densities with increasing N. S=1 junctions have four localized Sz=1/2 states at the end of each arm and centered on the junction, consistent with localized states in S=1 chains with finite Haldane gap. The GS of S=3/2 or 2 junctions of up to 500 spins is a spin density wave with increased amplitude at the ends of arms or near the junction. Quantum fluctuations completely suppress AF order in S=1/2 or 1 junctions, as well as in half-filled Hubbard junctions, but reduce rather than suppress AF order in S=3/2 or 2 junctions.
dc.description.sponsorshipM.K. thanks DST for support through Ramanujan Fellowship No. SR/S2/RJN-69/2012 and DST for funding computation facility through Grant No. SNB/MK/14-15/137. Z.G.S. thanks NSF for partial support of this work through the Princeton MRSEC (Grant No. DMR-0819860). S.R. thanks DST India for financial support.
dc.language.isoen
dc.publisherAmerican Physical Society (APS)
dc.relation.urlhttp://link.aps.org/doi/10.1103/PhysRevB.93.075107
dc.rightsArchived with thanks to Physical Review B
dc.titleEfficient density matrix renormalization group algorithm to study Y junctions with integer and half-integer spin
dc.typeArticle
dc.contributor.departmentKAUST Solar Center (KSC)
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.identifier.journalPhysical Review B
dc.eprint.versionPublisher's Version/PDF
dc.contributor.institutionS. N. Bose National Centre for Basic Sciences, Calcutta, Calcutta 700098, India
dc.contributor.institutionSolid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
dc.contributor.institutionDepartment of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)
dc.identifier.arxivid1508.03118
kaust.personThomas, Simil
refterms.dateFOA2018-06-13T11:30:46Z


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