12 research outputs found
Effective chiral-spin Hamiltonian for odd-numbered coupled Heisenberg chains
An system of odd number of coupled Heisenberg spin chains
is studied using a degenerate perturbation theory, where is the number of
coupled chains. An effective chain Hamiltonian is derived explicitly in terms
of two spin half degrees of freedom of a closed chain of sites, valid in
the regime the inter-chain coupling is stronger than the intra-chain coupling.
The spin gap has been calculated numerically using the effective Hamiltonian
for for a finite chain up to ten sites. It is suggested that the
ground state of the effective Hamiltonian is correlated, by examining
variational states for the effective chiral-spin chain Hamiltonian.Comment: 9 Pages, Latex, report ICTP-94-28
Class of exactly solvable SO(n) symmetric spin chains with matrix product ground states
We introduce a class of exactly solvable SO(n) symmetric Hamiltonians with
matrix product ground states. For an odd case, the ground state is a
translational invariant Haldane gap spin liquid state; while for an even case, the ground state is a spontaneously dimerized state with twofold
degeneracy. In the matrix product ground states for both cases, we identify a
hidden antiferromagnetic order, which is characterized by nonlocal string order
parameters. The ground-state phase diagram of a generalized SO(n) symmetric
bilinear-biquadratic model is discussed.Comment: 11 pages, 5 figure
The exactness of a general Skoda complex
We show that a Skoda complex with a general plurisubharmonic weight function
is exact if its 'degree' is sufficiently large. This answers a question of
Lazarsfeld and implies that not every integrally closed ideal is equal to a
multiplier ideal even if we allow general plurisubharmonic weights for the
multiplier ideal, extending the result of Lazarsfeld and Lee \cite{LL}.Comment: References added, exposition streamlined, to appear in Michigan
Mathematical Journa
Crystalizing the Spinon Basis
The quasi-particle structure of the higher spin XXZ model is studied. We
obtained a new description of crystals associated with the level integrable
highest weight modules in terms of the creation operators
at (the crystaline spinon basis). The fermionic character formulas and
the Yangian structure of those integrable modules naturally follow from this
description. We have also derived the conjectural formulas for the multi
quasi-particle states at .Comment: 25 pages, late
Exact Solution of Heisenberg-liquid models with long-range coupling
We present the exact solution of two Heisenberg-liquid models of particles
with arbitrary spin interacting via a hyperbolic long-range potential. In
one model the spin-spin coupling has the simple antiferromagnetic Heisenberg
exchange form, while for the other model the interaction is of the
ferromagnetic Babujian-Takhatajan type. It is found that the Bethe ansatz
equations of these models have a similar structure to that of the
Babujian-Takhatajan spin chain. We also conjecture the integrability of a third
new spin-lattice model with long-range interaction.Comment: 7pages Revte
Anyonic behavior of quantum group gases
We first introduce and discuss the formalism of -bosons and fermions
and consider the simplest Hamiltonian involving these operators. We then
calculate the grand partition function for these models and study the high
temperature (low density) case of the corresponding gases for . We show
that quantum group gases exhibit anyonic behavior in and spatial
dimensions. In particular, for a boson gas at the parameter
interpolates within a wider range of attractive and repulsive systems than the
anyon statistical parameter.Comment: LaTeX file, 19 pages, two figures ,uses epsf.st