We apply the coupled cluster method to high orders of approximation and exact diagonalizations to study the ground-state properties of the triangular-lattice spin-s Heisenberg antiferromagnet. We calculate the fundamental ground-state quantities, namely, the energy e0, the sublattice magnetization Msub, the in-plane spin stiffness ρs and the in-plane magnetic susceptibility χ for spin quantum n...

2014 A far infrared investigation of antiferromagnetic resonance by means of Fouriertransform spectroscopy has been carried out in FeCl2, FeBr2 and FeI2. In FeCl2 and FeBr2 our results are found to agree well with the two-sublattice model with an anisotropy parameter D = 9.6 K. In FeI2 three absorption peaks situated at 21.6 cm-1, 29.2 cm-1, and 32.2 cm-1 have been attributed to excitation of z...

We present an elementary method to construct optimized lattices that are used for finding small roots of polynomial equations. Former methods first construct some large lattice in a generic way from a polynomial f and then optimize via finding suitable smaller dimensional sublattices. In contrast, our method focuses on optimizing f first which then directly leads to an optimized small dimension...

In this review we highlight recent theoretical and experimental work on sublattice asymmetric doping of impurities in graphene, with a focus on substitutional nitrogen dopants. It is well known that one current limitation of graphene in regards to its use in electronics is that in its ordinary state it exhibits no band gap. By doping one of its two sublattices preferentially it is possible to n...

The transformation of SiO2 from low pressure tetrahedral phases into denser octahedral phases takes place via the collapse of the oxygen sublattice into a close-packed arrangement. The transition paths and the resulting products are known to be affected by the presence of anisotropic stresses, which are difficult to control, so interpretation of the experimental results is problematic. Based on...

The magnetic behavior of polycrystalline samples of Er(2)Ir(2)O(7) and Tb(2)Ir(2)O(7) pyrochlores is studied by magnetization measurements and neutron diffraction. Both compounds undergo a magnetic transition at 140 and 130 K, respectively, associated with an ordering of the Ir sublattice, signaled by thermomagnetic hysteresis. In Tb(2)Ir(2)O(7), we show that the Ir molecular field leads the Tb...

D. Lau raised the problem of determining the cardinality of the set of all partial clones of Boolean functions whose total part is a given Boolean clone. The key step in the solution of this problem, which was obtained recently by the authors, was to show that the sublattice of strong partial clones on {0, 1} that contain all total functions preserving the relation ρ0,2 = {(0, 0), (0, 1), (1, 0...

The material design with controlled structure was performed on titanium monoxide with structural vacancies on both sublattices. The polycrystalline powder of disordered titanium monoxide TiO0.98 with B1 structure was subjected to high pressures up to 60 kbar and high temperatures up to 2273 K. The X-ray powder diffraction of as-prepared and treated powders revealed cubic singlephase crystals. T...

The role of defect-induced zero-energy modes on charge transport in graphene is investigated using Kubo and Landauer transport calculations. By tuning the density of random distributions of monovacancies either equally populating the two sublattices or exclusively located on a single sublattice, all conduction regimes are covered from direct tunneling through evanescent modes to mesoscopic tran...

Mixed-valence phenomena associated with the highly correlated narrow-band behaviour of the 4f electrons in rare earths are well documented for a variety of rare-earth chalcogenides, borides and intermetallics (Kondo insulators and heavy fermions). The family of rare-earth fullerides with stoichiometry RE2.75C60 (RE=Sm, Yb, Eu) also displays an analogous phenomenology and a remarkable sensitivit...