2,163 research outputs found
Weak Ferromagnetic Exchange and Anomalous Specific Heat in ZnCu3(OH)6Cl2
Experimental evidence for a plethora of low energy spin excitations in the
spin-1/2 kagome antiferromagnet ZnCu3(OH)6Cl2 may be understandable in terms of
an extended Fermi surface of spinons coupled to a U(1) gauge field. We carry
out variational calculations to examine the possibility that such a state may
be energetically viable. A Gutzwiller-projected wavefunction reproduces the
dimerization of a kagome strip found previously by DMRG. Application to the
full kagome lattice shows that the inclusion of a small ferromagnetic
next-nearest-neighbor interaction favors a ground state with a spinon Fermi
surface.Comment: 4 pages, 3 figures, some clarifications to the tex
Statistics of the General Circulation from Cumulant Expansions
Large-scale atmospheric flows may not be so nonlinear as to preclude their
statistical description by systematic expansions in cumulants. I extend
previous work by examining a two-layer baroclinic model of the general
circulation. The fixed point of the cumulant expansion describes the
statistically steady state of the out-of-equilibrium model. Equal-time
statistics so obtained agree well with those accumulated by direct numerical
simulation.Comment: 1 page paper with 4 figures that accompanies one of the winning
entries in the APS gallery of nonlinear images competitio
Confinement of matter fields in compact (2+1)-dimensional QED theory of high- superconductors
We study confinement of matter fields in the effective compact
(2+1)-dimensional QED theory of high- superconductors. It is shown that
the monopole configurations do not affect the propagator of gauge potential
. Based on this result, we found that: chiral symmetry breaking and
confinement take place simultaneously in the antiferromagnetic state; neither
monopole effect nor Anderson-Higgs mechanism can cause confinement in the
d-wave superconducting state.Comment: 5 pages, no figure
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