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DOE OSTI · 21544567

Coupled-cluster method: A lattice-path-based subsystem approximation scheme for quantum lattice models

Bishop, R F·Li, P H. Y.
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Abstract

An approximation hierarchy, called the lattice-path-based subsystem (LPSUBm) approximation scheme, is described for the coupled-cluster method (CCM). It is applicable to systems defined on a regular spatial lattice. We then apply it to two well-studied prototypical (spin-(1/2) Heisenberg antiferromagnetic) spin-lattice models, namely, the XXZ and the XY models on the square lattice in two dimensions. Results are obtained in each case for the ground-state energy, the ground-state sublattice magnetization, and the quantum critical point. They are all in good agreement with those from such alternative methods as spin-wave theory, series expansions, quantum Monte Carlo methods, and the CCM using the alternative lattice-animal-based subsystem (LSUBm) and the distance-based subsystem (DSUBm) schemes. Each of the three CCM schemes (LSUBm, DSUBm, and LPSUBm) for use with systems defined on a regular spatial lattice is shown to have its own advantages in particular applications.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYANGULAR MOMENTUMANTIFERROMAGNETISMAPPROXIMATIONSCALCULATION METHODSCLUSTER MODELCRYSTAL LATTICESCRYSTAL STRUCTUREMAGNETISMMAGNETIZATIONMATHEMATICAL MODELSMECHANICSMONTE CARLO METHODNUCLEAR MODELSPARTICLE PROPERTIESQUANTUM MECHANICSSERIES EXPANSIONSPINSPIN WAVESTETRAGONAL LATTICES

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Bishop, R F, Li, P H. Y.. 2011-04-15. Coupled-cluster method: A lattice-path-based subsystem approximation scheme for quantum lattice models. https://doi.org/10.1103/physreva.83.042111

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