Concept

Lattice (group)

Related publications (163)

Doping quantum dimer models on the square lattice

A family of models is proposed to describe the motion of holes in a fluctuating quantum dimer background on the square lattice. Following Castelnovo et al. [Ann. Phys. (N.Y.) 318, 316 (2005)], a generalized Rokhsar-Kivelson Hamiltonian at finite doping whi ...

2006

Quadrupolar Phases of theS=1Bilinear-Biquadratic Heisenberg Model on the Triangular Lattice

Frédéric Mila, Karlo Penc

Using mean-field theory, exact diagonalizations, and SU(3) flavor theory, we have precisely mapped out the phase diagram of the S=1 bilinear-biquadratic Heisenberg model on the triangular lattice in a magnetic field, with emphasis on the quadrupolar phases ...

2006

Hexagonal Versus Orthogonal Lattices: A New Comparison Using Approximation Theory

Dimitri Nestor Alice Van De Ville, Thierry Blu

We provide a new comparison between hexagonal and orthogonal lattices, based on approximation theory. For each of the lattices, we select the “natural” spline basis function as generator for a shift-invariant function space; i.e., the tensor-product B-spli ...

IEEE2005

Hex-Splines: A Novel Spline Family for Hexagonal Lattices

Michaël Unser, Dimitri Nestor Alice Van De Ville, Thierry Blu

This paper proposes a new family of bivariate, non-separable splines, called hex-splines, especially designed for hexagonal lattices. The starting point of the construction is the indicator function of the Voronoi cell, which is used to define in a natural ...

IEEE2004

Comparison of the In distribution in InGaN/GaN quantum well structures grown by molecular beam epitaxy and metalorganic vapor phase epitaxy

Nicolas Grandjean

We have compared the In distribution in InGaN quantum wells grown by molecular beam epitaxy (MBE) and metalorganic vapor phase epitaxy (MOVPE). The samples were studied by conventional and high-resolution transmission electron microscopy (HRTEM). The local ...

2004

Proton insertion in polycrystalline WO3 studied with electron spectroscopy and semi-empirical calculations

Ulf Anders Hagfeldt

Proton insertion in polycryst. tungsten oxide has been studied with photoelectron spectroscopy and semi-empirical calcns. The W 4f spectra show growth of W5+ and W4+ oxidn. states as a function of inserted proton content in the crystal lattice. A concomita ...

2004

A molecular dynamics study of an incommensurate modulation compound: 4,4 '-dichlorobiphenyl sulphone

Gervais Chapuis

A molecular dynamics simulation of 4, 4'-dichlorobiphenyl sulfone was carried out in order to study the phase transition from a normal to incommensurate modulated phase observed experimentally. Agreements of simulated and experimental diffraction patterns ...

2004

Cluster synchronization in three-dimensional lattices of diffusively coupled oscillators

Martin Hasler, Igor Belykh

Cluster synchronization modes of continuous time oscillators that are diffusively coupled in a three-dimensional (3-D) lattice are studied in the paper via the corresponding linear invariant manifolds. Depending in an essential way on the number of oscilla ...

2003

The commensurate composite sigma-structure of beta-tantalum

Gervais Chapuis, Alla Arakcheeva, Philip Pattison

The single-crystal investigation of the self-hosting sigma-structure of beta-tantalum (beta-Ta) at 120 K (low-temperature, LT, structure) and at 293 K (RT-I before cooling and RT-II after cooling and rewarming; RT represents room temperature) shows that th ...

2003

On the Approximation Power of Splines: Orthogonal Versus Hexagonal Lattices

Michaël Unser, Dimitri Nestor Alice Van De Ville, Thierry Blu

Recently, we have proposed a novel family of bivariate, non-separable splines. These splines, called "hexsplines" have been designed to deal with hexagonally sampled data. Incorporating the shape of the Voronoi cell of a hexagonal lattice, they preserve th ...

NuHAG2003

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