176,238 research outputs found
Renormalization Group Technique Applied to the Pairing Interaction of the Quasi-One-Dimensional Superconductivity
A mechanism of the quasi-one-dimensional (q1d) superconductivity is
investigated by applying the renormalization group techniques to the pairing
interaction. With the obtained renormalized pairing interaction, the transition
temperature Tc and corresponding gap function are calculated by solving the
linearized gap equation. For reasonable sets of parameters, Tc of p-wave
triplet pairing is higher than that of d-wave singlet pairing due to the
one-dimensionality of interaction. These results can qualitatively explain the
superconducting properties of q1d organic conductor (TMTSF)2PF6 and the ladder
compound Sr2Ca12Cu24O41.Comment: 18 pages, 9 figures, submitted to J. Phys. Soc. Jp
Bose-Einstein Correlations for Mixed Neutral Mesons
Correlations are shown to arise in nonidentical mixed-particle pairs like
when observed in identical decay modes like in
multiparticle final states containing many partial waves. No enhancement is
found in any single partial wave and all partial wave analyses of the s-wave
threshold resonance and should give the same results for all decay
modes. In CP violation experiments where pairs are inclusively
produced and correlated decays into and leptonic modes are observed,
the CP-violating lepton asymmetry is enhanced by a factor of two in the
kinematic region where Bose enhancement occurs.Comment: 11 page
Low Temperature AC Conductivity in BSCCO (2212)
We report measurements of anamolously large dissipative conductivities in
BiSrCaCuO(2212) at low temperatures. We have measured the complex conductivity
of BSCCO thin films at 100-600 GHz as a function of doping from the underdoped
to the overdoped state. At low temperatures there exists a residual dissipative
conductivity which scales with the T=0 superfluid density as the doping is
varied. This residual dissipative conductivity is larger than the possible
contribution from a thermal population of quasiparticles at the d-wave gap
nodes.Comment: Submitted to the Proceedings of the 22nd International Low
Temperature Physics Conference. To be published in Physica B
(http://www.elsevier.nl/locate/physb); 2 Pages with 2 Figure
Robustness of the avalanche dynamics in data packet transport on scale-free networks
We study the avalanche dynamics in the data packet transport on scale-free
networks through a simple model. In the model, each vertex is assigned a
capacity proportional to the load with a proportionality constant . When
the system is perturbed by a single vertex removal, the load of each vertex is
redistributed, followed by subsequent failures of overloaded vertices. The
avalanche size depends on the parameter as well as which vertex triggers
it. We find that there exists a critical value at which the avalanche
size distribution follows a power law. The critical exponent associated with it
appears to be robust as long as the degree exponent is between 2 and 3, and is
close in value to that of the distribution of the diameter changes by single
vertex removal.Comment: 5 pages, 7 figures, final version published in PR
Charge ordering in doped manganese oxides: lattice dynamics and magnetic structure
Based on the Hamiltonian of small polarons with the strong nearest neighbor
repulsion, we have investigated the charge ordering phenomena observed in
half-doped manganites R_{1/2}A_{1/2}MnO_3. We have explored possible
consequences of the charge ordering phase in the half-doped manganites. First,
we have studied the renormalization of the sound velocity around ,
considering the acoustic phonons coupled to the electrons participating in the
charge ordering. Second, we have found a new antiferromagnetic phase induced by
the charge ordering, and discussed its role in connection with the specific
CE-type antiferromagnetic structure observed in half-doped manganites.Comment: 5 pages, 2 Postscript figures. To appear in Phys. Rev. B - Rapid
Comm. (01Jun97
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