3,599 research outputs found
Nonlinear dynamics in superlattices driven by high frequency ac-fields
We investigate the dynamical processes taking place in nanodevices driven by
high-frequency electromagnetic fields. We want to elucidate the role of
different mechanisms that could lead to loss of quantum coherence. Our results
show how the dephasing effects of disorder that destroy after some periods
coherent oscillations, such as Rabi oscillations, can be overestimated if we do
not consider the electron-electron interactions that can reduce dramatically
the decoherence effects of the structural imperfections. Experimental
conditions for the observation of the predicted effects are discussed.Comment: REVTEX (8 pages) and 4 figures (Postscript
Polariton Local States in Periodic Bragg Multiple Quantum Well Structures
We analytically study optical properties of several types of defects in Bragg
multiple quantum well structures. We show that a single defect leads to two
local polariton modes in the photonic band gap. These modes lead to
peculiarities in reflection and transmission spectra. Detailed recommendations
for experimental observation of the studied effects are given.Comment: 3 pages, 1 figure, RevTex, Submitted to Opt. Let
Impurity-induced polaritons in a one-dimensional chain
A detailed analytical study of an impurity induced polariton band arising
inside a spectral gap between lower and upper polariton branches is presented.
Using the microcanonical method, we calculate the density of states and
localization length of the impurity polaritons. Analytical results are compared
with numerical simulations and excellent agreement is found.Comment: 10 pages, 3 figures, RevTe
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