Hierarchical mean-field approach to theJ1−J2Heisenberg model on a square lattice

Density-wave patterns for fermionic dipolar molecules on a square optical lattice: Mean-field-theory analysis

We model a system of ultracold fermionic dipolar molecules on a two-dimensional square lattice. Assuming that the molecules are in their nondegenerate hyperfine ground state, and that the dipole moment is polarized perpendicular to the plane (as in the recent experiments on 40K-87Rb molecules), we approximate these molecules as spinless fermions with long-range repulsive dipolar interactions. W...

Mean-field lattice trees

We introduce a mean-field model of lattice trees based on embeddings into Zd of abstract trees having a critical Poisson offspring distribution. This model provides a combinatorial interpretation for the self-consistent mean-field model introduced previously by Derbez and Slade, and provides an alternate approach to work of Aldous. The scaling limit of the mean-field model is integrated superBr...

Uniaxially anisotropic antiferromagnets in a field on a square lattice

Classical uniaxially anisotropic Heisenberg and XY antiferromagnets in a field along the easy axis on a square lattice are analysed, applying ground state considerations and Monte Carlo techniques. The models are known to display antiferromagnetic and spin–flop phases. In the Heisenberg case, a single– ion anisotropy is added to the XXZ antiferromagnet, enhancing or competing with the uniaxial ...

A Lattice-Based Approach to Hierarchical Clustering

The paper presents an approach to hierarchical clustering based on the use of a least general generalization (lgg) operator to induce a lattice structure of clusters and a category utility objective function to evaluate the clustering quality. The objective function is integrated with a lattice-based distance measure into a bottom-up control strategy for clustering. Experiments with well-known ...

Hierarchical Mean-field Theories