Ab initio calculations for the square-lattice anisotropic Heisenberg model

R. F. Bishop, DJJ Farnell

    Research output: Contribution to journalArticlepeer-review

    86 Downloads (Pure)

    Abstract

    Interest in lattice quantum spin systems as models of quantum magnets has increased with the discovery of new and interesting magnetic materials. Here we use a well-known technique of quantum many-body theory, namely the coupled-cluster method (CCM), to investigate the nearest-neighbour, spin-1/2, anisotropic Heisenberg model on the square lattice. Ground-state expectation values for quantities such as the ground-state energy and the sublattice magnetisation are determined to an accuracy comparable with that of the best of other available techniques including Monte Carlo methods. In order to demonstrate this point we present results for various values of the anisotropy parameter, including those for the Isotropie Heisenberg model and the isotropic XY model. We show that it is now possible to determine the presence and position of the quantum phase transitions using ab initio CCM calculations, and furthermore that we can accurately predict the critical behaviour at these points.
    Original languageEnglish
    Pages (from-to)709-719
    Number of pages11
    JournalInternational Journal of Modern Physics B
    Volume13
    DOIs
    Publication statusPublished - 1999

    Keywords

    • COUPLED-CLUSTER METHOD; GROUND-STATE ENERGY; QUANTUM ANTIFERROMAGNETS; XXZ MODELS; SPIN;

    Fingerprint

    Dive into the research topics of 'Ab initio calculations for the square-lattice anisotropic Heisenberg model'. Together they form a unique fingerprint.

    Cite this