Quantum disorder in the two-dimensional pyrochlore Heisenberg antiferromagnet
ArXiv cond-mat/0102447 (2001)
Abstract:
We present the results of an exact diagonalization study of the spin-1/2 Heisenberg antiferromagnet on a two-dimensional version of the pyrochlore lattice, also known as the square lattice with crossings or the checkerboard lattice. Examining the low energy spectra for systems of up to 24 spins, we find that all clusters studied have non-degenerate ground states with total spin zero, and big energy gaps to states with higher total spin. We also find a large number of non-magnetic excitations at energies within this spin gap. Spin-spin and spin-Peierls correlation functions appear to be short-ranged, and we suggest that the ground state is a spin liquid.Effective potentials for polymers and colloids: Beyond the van der Waals picture of fluids?
(2001)
Finite-temperature dynamical magnetic susceptibility of quasi-one-dimensional frustrated spin-1/2 Heisenberg antiferromagnets
(2001)
Casimir Torques between Anisotropic Boundaries in Nematic Liquid Crystals
ArXiv cond-mat/0102099 (2001)
Abstract:
Fluctuation-induced interactions between anisotropic objects immersed in a nematic liquid crystal are shown to depend on the relative orientation of these objects. The resulting long-range ``Casimir'' torques are explicitely calculated for a simple geometry where elastic effects are absent. Our study generalizes previous discussions restricted to the case of isotropic walls, and leads to new proposals for experimental tests of Casimir forces and torques in nematics.Correlated adaptation of agents in a simple market: a statistical physics perspective
Quantitative Finance Taylor & Francis 1:2 (2001) 246-253