1,306 research outputs found
Surface EM waves on 1D Photonic Crystals
We study surface states of 1D photonic crystals using a semiclassical coupled
wave theory. Both TE and TM modes are treated. We derive analytic
approximations that clarify the systematics of the dispersion relations, and
the roles of the various parameters defining the crystal.Comment: 7 pages, 8 figure
A model for single electron decays from a strongly isolated quantum dot
Recent measurements of electron escape from a non-equilibrium charged quantum
dot are interpreted within a 2D separable model. The confining potential is
derived from 3D self-consistent Poisson-Thomas-Fermi calculations. It is found
that the sequence of decay lifetimes provides a sensitive test of the confining
potential and its dependence on electron occupation.Comment: 9 pages, 10 figure
Enhanced observability of quantum post-exponential decay using distant detectors
We study the elusive transition from exponential to post-exponential
(algebraic) decay of the probability density of a quantum particle emitted by
an exponentially decaying source, in one dimension. The main finding is that
the probability density at the transition time, and thus its observability,
increases with the distance of the detector from the source, up to a critical
distance beyond which exponential decay is no longer observed. Solvable models
provide explicit expressions for the dependence of the transition on resonance
and observational parameters, facilitating the choice of optimal conditions
Classical picture of post-exponential decay
Post-exponential decay of the probability density of a quantum particle
leaving a trap can be reproduced accurately, except for interference
oscillations at the transition to the post-exponential regime, by means of an
ensemble of classical particles emitted with constant probability per unit time
and the same half-life as the quantum system. The energy distribution of the
ensemble is chosen to be identical to the quantum distribution, and the
classical point source is located at the scattering length of the corresponding
quantum system. A 1D example is provided to illustrate the general argument
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