Related papers: Low-temperature orientational order and possible d…
Using a Monte Carlo method, we study the finite-temperature phase transition in the two-dimensional classical Heisenberg model on a triangular lattice with or without easy-plane anisotropy. The model takes account of competing interactions:…
The spin-1/2 Cu2+ ions in beta-Cu3V2O8 occupy the sites of a Kagome-staircase lattice, an anisotropic variant of the Kagome net: buckled layers and imbedded plaquettes of three edge-shared CuO4 squares break the ideal Kagome symmetry.…
The problem of the orientational ordering transition for lattice-gas models of liquid crystals is discussed in the low-dimensional case $d=1,2$. For isotropic short-range interactions, orientational long-range order at finite temperature is…
Motivated by the recent interest in the possible ordering of the CH$_3$NH$_3$ dipoles in the material CH$_3$NH$_3$PbI$_3$, we investigate the properties of domain boundaries in a simple cubic lattice of dipoles. We perform numerical…
Interesting emergent behavior in quantum materials arises when the interaction of electrons with the lattice leads to partial localization and ordering of charge at low temperatures. The triangular lattice of some transition metal…
We extend the Su-Schrieffer-Heeger model of polyacetylene to C_{60} and C_{70} molecules, and solve numerically. The calculations of the undoped systems agree well with the known results. When the system (C_{60} or C_{70}) is doped with one…
We synthesize and spectroscopically investigate monolayer C$_{60}$ on the topological insulator (TI) Bi$_4$Te$_3$. This C$_{60}$/Bi$_4$Te$_3$ heterostructure is characterized by excellent translational order in a novel (4 x 4) C$_{60}$…
Exchange interaction tends to favor collinear or coplanar magnetic orders in rotationally invariant spin systems. Indeed, such magnetic structures are usually selected by thermal or quantum fluctuations in highly frustrated magnets. Here we…
Self-assembly of particles with short-range attraction and long-range repulsion (SALR) interactions on a flat and on a spherical surface is compared. Molecular dynamics (MD) simulations are performed for the two systems having the same area…
We perform a general study of spin ordering on the pyrochlore lattice with a 3:1 proportionality of two spin polarizations. Equivalently, this describes valence bond solid conformations of a quantum dimer model on the diamond lattice. We…
In the present paper, we have studied atomic structure of nitrogenous austenite. High precision ab-initio calculation was utilized for the calculation of the pair potentials of interatomic interactions N-N in FCC Fe lattice. These…
We study the classical version of the 120-degree model. This is an attractive nearest-neighbor system in three dimensions with XY (rotor) spins and interaction such that only a particular projection of the spins gets coupled in each…
Vanadium Sesquioxide (V$_2$O$_3$) is an antiferromagnetic insulator below $T_{\mathrm N}\approx$ 155 K. The magnetic order is not of C- or G-type as one would infer from the bipartite character of the hexagonal basal plane in the…
Dimer C60 solids are monoclinic crystals with molecular longer axis aligned along the c-axis. A simple model based on atom-atom potential used to calculate various bulk, structural and thermodynamic properties of this fullerite, has also…
The improper ferroelectricity in YMnO$_3$ and other related multiferroic hexagonal manganites are known to cause topologically protected ferroelectric domains that give rise to rich and diverse physical phenomena. The local structure and…
We show in a simple model of interlayer hopping of single electrons, that transport along the weakly coupled c-axis of quasi-two-dimensional metals does not always probe only the in-plane electron properties. In our model where there is a…
We set forth the structural and magnetic properties of the frustrated spin-$5/2$ triangle lattice antiferromagnet Na$_3$Fe(PO$_4$)$_2$ examined via x-ray diffraction, magnetization, heat capacity, and neutron diffraction measurements on the…
We study the dynamics of nanocrystals composed of C60 fullerene molecules. We demonstrate that such structures can support long-lived strongly localized nonlinear oscillatory modes, which resemble discrete breathers in simple lattices. We…
We propose a simple microscopic model of molecular dynamics simulation to study orientational glass in three dimensions. We present simulation results for mixtures of mildly anisotropic particles and spherical impurities. We realize fcc…
In this paper we have considered a simple lattice gas model of chemisorbed monolayer which allows for the harmonic fluctuations of the bond length between the adsorbate atom and the surface site. The model also involves a short-ranged…