1,477 research outputs found
Quantum melting of charge ice and non-Fermi-liquid behavior: An exact solution for the extended Falicov-Kimball model in the ice-rule limit
An exact solution is obtained for a model of itinerant electrons coupled to
ice-rule variables on the tetrahedron Husimi cactus, an analogue of the Bethe
lattice of corner-sharing tetrahedra. It reveals a quantum critical point with
the emergence of non-Fermi-liquid behavior in melting of the "charge ice"
insulator. The electronic structure is compared with the numerical results for
the pyrochlore-lattice model to elucidate the physics of electron systems
interacting with the tetrahedron ice rule.Comment: 5 pages, 4 figure
Large renal aneurysm successfully treated by percutaneous embolization using detachable steel coils
The definitive version is available at www.blackwell-synergy.com.ArticleInternational Journal of Urology. 13(7): 993-994 (2006)journal articl
Thermally-induced magnetic phases in an Ising spin Kondo lattice model on a kagome lattice at 1/3-filling
Numerical investigation on the thermodynamic properties of an Ising spin
Kondo lattice model on a kagome lattice is reported. By using Monte Carlo
simulation, we investigated the magnetic phases at 1/3-filling. We identified
two successive transitions from high-temperature paramagnetic state to a
Kosterlitz-Thouless-like phase in an intermediate temperature range and to a
partially disordered phase at a lower temperature. The partially disordered
state is characterized by coexistence of antiferromagnetic hexagons and
paramagnetic sites with period . We compare the results
with those for the triangular lattice case.Comment: 4 pages, 2 figure
Pion decay constant for the Kogut-Susskind quark action in quenched lattice QCD
We present a study for the pion decay constant in the quenched
approximation to lattice QCD with the Kogut-Susskind (KS) quark action, with
the emphasis given to the renormalization problems. Numerical simulations are
carried out at the couplings and 6.2 on and
lattices, respectively. The pion decay constant is evaluated
for all KS flavors via gauge invariant and non-invariant axial vector currents
with the renormalization constants calculated by both non-perturbative method
and perturbation theory. We obtain MeV in the continuum limit
as the best value using the partially conserved axial vector current, which
requires no renormalization. From a study for the other KS flavors we find that
the results obtained with the non-perturbative renormalization constants are
well convergent among the KS flavors in the continuum limit, confirming
restoration of flavor symmetry, while perturbative
renormalization still leaves an apparent flavor breaking effect even in the
continuum limit.Comment: LaTex, 27 pages, 35 eps figures, uses revtex and eps
One Spin Trace Formalism for
It has been known for some time that there are two methods to calculate with staggered fermions: one is the two spin trace formalism and the other is
the one spin trace formalism. Until now, the two spin trace formalism has been
exclusively used for weak matrix element calculations with staggered fermions.
Here, the one spin trace formalism to calculate with staggered fermions
is explained. It is shown that the one spin trace operators require additional
chiral partner operators in order to keep the continuum chiral behavior. The
renormalization of the one spin trace operators is described and compared with
the two spin trace formalism.Comment: 47 pages, latex, 4 figures are available on reques
Chiral behaviour of the lattice -parameter with the Wilson and Clover Actions at
We present results for the kaon -parameter from a sample of
configurations using the Wilson action and configurations using the
SW-Clover action, on a lattice at . We compare
results obtained by renormalizing the relevant operator with different
``boosted" values of the strong coupling constant . In the case of
the SW-Clover action, we also use the operator renormalized non-perturbatively.
In the Wilson case, we observe a strong dependence of on the prescription
adopted for , contrary to the results of the Clover case which are
almost unaffected by the choice of the coupling. We also find that the matrix
element of the operator renormalized non-perturbatively has a better chiral
behaviour. This gives us our best estimate of the renormalization group
invariant -parameter, .Comment: LaTeX, 17 pages, 3 postscript figures uuencode
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