1,141 research outputs found
Mott Transitions of Three-Component Fermionic Atoms with Repulsive Interaction in Optical Lattices
We investigate the Mott transitions of three-component (colors) repulsive
fermionic atoms in optical lattices using the dynamical mean field theory. We
find that for SU(3) symmetry breaking interactions the Mott transition occurs
at incommensurate half filling. As a result, a characteristic Mott insulating
state appears, where paired atoms with two different colors and atoms with the
third color are localized at different sites. We also find another Mott state
where atoms with two different colors are localized at different sites and
atoms with the third color remain itinerant. We demonstrate that these exotic
Mott phases can be detected by experimental double occupancy observations.Comment: 5 pages, 4 figure
Longitudinal development of muons in large air showers studies from the arrival time distributions measured at 900m above sea level
The arrival time distributions of muons with energies above 1.0GeV and 0.5GeV have been measured in the Akeno air-shower array to study the longitudinal development of muons in air showers with primary energies in the range 10 to the 17th power to 10 to the 18th power ev. The average rise times of muons with energies above 1.0GeV at large core distances are consistent with those expected from very high multiplicity models and, on the contrary, with those expected from the low multiplicity models at small core distances. This implies that the longitudinal development at atmospheric depth smaller than 500 cm square is very fast and that at larger atmospheric depths is rather slow
Arrival time distributions of electrons in air showers with primary energies above 10 (18)eV observed at 900m above sea level
Detection of air showers with primary energies above 10 to the 19th power eV with sufficient statistics is extremely important in an astrophysical aspect related to the Greisen cut off and the origin of such high energy cosmic rays. Recently, a method is proposed to observe such giant air showers by measuring the arrival time distributions of air-shower particles at large core distances with a mini array. Experiments to measure the arrival time distributions of muons were started in 1981 and those of electrons in early 1983 in the Akeno air-shower array (930 gcm cm squared atmospheric depth, 900m above sea level). During the time of observation, the detection area of the Akeno array was expanded from 1 sq km to sq km in 1982 and to 20 sq km in 1984. Now the arrival time distribution of electrons and muons can be measured for showers with primary energies above 1019eV at large core distances
Supersolid state in fermionic optical lattice systems
We study ultracold fermionic atoms trapped in an optical lattice with
harmonic confinement by combining the real-space dynamical mean-field theory
with a two-site impurity solver. By calculating the local particle density and
the pair potential in the systems with different clusters, we discuss the
stability of a supersolid state, where an s-wave superfluid coexists with a
density-wave state of checkerboard pattern. It is clarified that a confining
potential plays an essential role in stabilizing the supersolid state. The
phase diagrams are obtained for several effective particle densities.Comment: 7 pages, 5 figures, Phys. Rev. A in pres
Anomalous magnetic properties near Mott transition in Kagom\'e lattice Hubbard model
We investigate the characteristics of the metallic phase near the Mott
transition in the Kagom\'e lattice Hubbard model using the cellular dynamical
mean field theory. By calculating the specific heat and spin correlation
functions, we demonstrate that the quasiparticles show anomalous properties in
the metallic phase close to the Mott transition. We find clear evidence for the
multi-band heavy quasiparticles in the specific heat, which gives rise to
unusual temperature dependence of the spin correlation functions.Comment: 2 pages, 3 figures, accepted for publication in J. Mag. Mag. Mater.
(Proceedings of the ICM, Kyoto, Japan, August 2006
Possible Kondo resonance in PrFe4P12 studied by bulk-sensitive photoemission
Pr 4f electronic states in Pr-based filled skutterudites PrT4X12(T=Fe and Ru;
X=P and Sb) have been studied by high-resolution bulk-sensitive Pr 3d-4f
resonance photoemission. A very strong spectral intensity is observed just
below the Fermi level in the heavy-fermion system PrFe4P12. The increase of its
intensity at lower temperatures is observed. We speculate that this is the
Kondo resonance of Pr, the origin of which is attributed to the strong
hybridization between the Pr 4f and the conduction electrons.Comment: 4 pages(camera ready format), 4 figures, ReVTeX
Wall effects on pressure fluctuations in turbulent channel flow
The purpose of the present paper is to study the influence of wall-echo on
pressure fluctuations , and on statistical correlations containing ,
{\em viz} redistribution , pressure diffusion , and
velocity/pressure-gradient . We extend the usual analysis of
turbulent correlations containing pressure fluctuations in wall-bounded
\tsc{dns} computations [Kim J.: {\em J. Fluid Mech.} {\bf 205} (1989)
421--451], separating not only into rapid and slow
parts [Chou P.Y.: {\em Quart. Appl. Math.} {\bf 3} (1945)
38--54], but further into volume ( and
) and surface (wall-echo;
and ) terms. An algorithm, based on a Green's function
approach, is developed to compute the above splittings for various correlations
containing pressure fluctuations (redistribution, pressure diffusion,
velocity/pressure-gradient), in fully developed turbulent plane channel flow.
This exact analysis confirms previous results based on a method-of-images
approximation [Manceau R., Wang M., Laurence D.: {\em J. Fluid Mech.} {\bf 438}
(2001) 307--338] showing that, at the wall, and
are usually of the same sign and approximately equal. The above
results are then used to study the contribution of each mechanism on the
pressure correlations in low Reynolds-number plane channel flow, and to discuss
standard second-moment-closure modelling practices
Finite-temperature Mott transitions in multi-orbital Hubbard model
We investigate the Mott transitions in the multi-orbital Hubbard model at
half-filling by means of the self-energy functional approach. The phase
diagrams are obtained at finite temperatures for the Hubbard model with up to
four-fold degenerate bands. We discuss how the first-order Mott transition
points and as well as the critical temperature depend
on the orbital degeneracy. It is elucidated that enhanced orbital fluctuations
play a key role to control the Mott transitions in the multi-orbital Hubbard
model.Comment: 8 pages, 7 figure
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