24,020 research outputs found
Classical and quantum interference in multiband optical Bloch oscillations
Classical and quantum interference of light propagating in arrays of coupled
waveguides and undergoing multiband optical Bloch oscillations (BOs) with
negligible Zener tunneling is theoretically investigated. In particular, it is
shown that Mach-Zehnder-like interference effects spontaneously arise in
multiband BOs owing to beam splitting and subsequent beam recombination
occurring in one BO cycle. As a noteworthy example of quantum interference, we
discuss the doubling of interference fringes in photon counting rates for a
correlated photon pair undergoing two-band BOs, a phenomenon analogous to the
manifestation of the de Broglie wavelength of an entangled biphoton state
observed in quantum Mach-Zehnder interferometry.Comment: 11 pages, 4 figure
Reverse and dual Loomis-Whitney-type inequalities
Various results are proved giving lower bounds for the th intrinsic volume
, , of a compact convex set in , in
terms of the th intrinsic volumes of its projections on the coordinate
hyperplanes (or its intersections with the coordinate hyperplanes). The bounds
are sharp when and . These are reverse (or dual, respectively)
forms of the Loomis-Whitney inequality and versions of it that apply to
intrinsic volumes. For the intrinsic volume , which corresponds to mean
width, the inequality obtained confirms a conjecture of Betke and McMullen made
in 1983
Damage in Fiber Bundle Models
We introduce a continuous damage fiber bundle model that gives rise to
macroscopic plasticity and compare its behavior with that of dry fiber bundles.
Several interesting constitutive behaviors are found in this model depending on
the value of the damage parameter and on the form of the disorder distribution.
In addition, we compare the behavior of global load transfer models with local
load transfer models and study in detail the damage evolution before failure.
We emphasize the analogies between our results and spinodal nucleation in
first-order phase transitions.Comment: 9 pages, 13 figures (ps, eps
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