Related papers: Propagating S=1/2 particles in S=1 Haldane gap sys…
A theoretical model is presented to explain the spin gap observed for CaV$_4$O$_9$. The underlying lattice of the 1/5-depleted square lattice favors a formation of plaquette resonating valence bond state. Inclusion of the frustrating second…
Every singlet state of a quantum spin 1/2 system can be decomposed into a linear combination of valence bond basis states. The range of valence bonds within this linear combination as well as the correlations between them can reveal the…
In current scientific and technological scenario, studies of transmittance of surface waves across structured interfaces have gained some wind amidst applications to metasurfaces, electronic edge-waves, crystal grain boundaries, etc. The…
By introducing arbitrary parameters in the usual Fronsdal model, we find a region in the parameters space away from the ``Fronsdal point'' where we still have an irreducible description of massless particles of arbitrary integer spin $s\ge…
We present a series expansion study of spin-S square-lattice Heisenberg antiferromagnets. The numerical data are in excellent agreement with recent neutron scattering measurements. Our key result is that the correlation length for S>1/2…
We calculate the antiferromagnetic spin wave dispersion in the half-filled (electronic density n=1) Hubbard model for a two-dimensional square lattice, using the random phase approximation (RPA) in a broken symmetry (spin density wave)…
A Haag-Ruelle scattering theory for particles with braid group statistics is developed, and the arising structure of the Hilbert space of multiparticle states is analyzed.
The Aharonov Bohm scattering for spinless, isospin 1/2, particles interacting through a nonabelian Chern-Simons field is studied. Starting from the relativistic quantum field theory and using a Coulomb gauge formulation, the one loop…
In this paper we use a constructive approach based on gauge invariant description of massive high spin particles for investigation of possible interactions of massive spin 2 particle. We work with general case of massive spin 2 particle…
We study the nonequilibrium steady-state of interacting photons in cavity arrays as described by the driven-dissipative Bose-Hubbard and spin-$1/2$ XY model. For this purpose, we develop a self-consistent expansion in the inverse…
Huygens sources are elements that scatter light in the forward direction as used in the Huygens-Fresnel principle. They have remained fictitious until recently where experimental systems have been fabricated. In this letter, we propose…
We study the evolution of the dynamical spin structure factor in a spin-1 antiferromagnetic Heisenberg chain which is randomly doped with spin-1/2 moments. Using stochastic series expansion Quantum Monte Carlo simulations combined with the…
We consider a collection of fully coupled weakly interacting diffusion processes moving in a two-scale environment. We study the moderate deviations principle of the empirical distribution of the particles' positions in the combined limit…
We study quantum quenches in the $S=1$ Heisenberg spin chain and show that the dynamics can be described by the recently developed semi-semiclassical method based on particles propagating along classical trajectories but scattering quantum…
We study interference effects in the dynamics of a spin-$1/2$ particle propagating in two dimensions in a disordered potential and subject to a generalized spin-orbit coupling. With the particle initially in a spin-polarized plane wave…
Using equivalencies between different models we reduce the model of two spin-1/2 Heisenberg chains crossed at one point to the model of free fermions. The spin-spin correlation function is calculated by summing the perturbation series in…
We study the low energy spectrum of the nearest neighbor Heisenberg model on a square lattice as a function of the total spin S. By quantum Monte Carlo simulation we compute this spectrum for the s=1/2, s=1 and s=3/2 Heisenberg models. We…
We consider the Kondo-Hubbard model with ferromagnetic exchange coupling $% J_{H}$, showing that it is an approximate effective model for late transition metal-O linear systems. We study the dependence of the charge and spin gaps…
We investigate doping of a two-orbital chain with mobile $S=1/2$ fermions as a valid model for $\rm Y_{2-x}Ca_xBaNiO_5$. The S=1 spins are stabilized by strong, ferromagnetic (fm) Hund's rule couplings. We calculate correlation functions…
An exact analytical solution of the decaying wave function of two identical noninteracting particles, which are entangled by spatial symmetry, is used to analyze the effect of the resonance spectra in the propagation of the decaying…