2,050 research outputs found
Localized exciton-polariton modes in dye-doped nanospheres: a quantum approach
We model a dye-doped polymeric nanosphere as an ensemble of quantum emitters
and use it to investigate the localized exciton-polaritons supported by such a
nanosphere. By determining the time evolution of the density matrix of the
collective system, we explore how an incident laser field may cause transient
optical field enhancement close to the surface of such nanoparticles. Our
results provide further evidence that excitonic materials can be used to good
effect in nanophotonics.Comment: 16 pages, 4 figure
Effective Yukawa Couplings in Noncompact Lattice QED
We investigate effective Yukawa couplings of mesons to the elementary
fermions in noncompact lattice QED. The couplings are extracted from suitable
fermion-antifermion-meson three-point functions calculated by Monte Carlo
simulations with dynamical staggered fermions. The scaling behaviour is
compatible with expectations from perturbation theory, thus indicating
triviality of QED. The lines of constant Yukawa coupling are compared to flows
of other quantities. Consistency is seen, at most, for weak coupling.Comment: 12 pages, uuencoded compressed postscrip
Is the Chiral Phase Transition in Non-Compact Lattice QED Driven by Monopole Condensation?
We investigate the recent conjecture that the chiral phase transition in
non-compact lattice QED is driven by monopole condensation. The comparison of
analytic and numerical results shows that we have a quantitative understanding
of monopoles in both the quenched and dynamical cases. We can rule out monopole
condensation.Comment: 21 pages, 10 postscript figures include
The SU(3) Beta Function from Numerical Stochastic Perturbation Theory
The SU(3) beta function is computed from Wilson loops to 20th order numerical
stochastic perturbation theory. An attempt is made to include massless
fermions, whose contribution is known analytically to 4th order. The question
whether the theory admits an infrared stable fixed point is addressed.Comment: 10 pages, 7 figures, version to be published in Physics Letters
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