8,593 research outputs found
Estimation of the particle-antiparticle correlation effect for pion production in heavy ion collisions
Estimation of the back-to-back pi-pi correlations arising due to evolution of
the pionic field in the course of pion production process is given for central
heavy nucleus collisions at moderate energies.Comment: 6 LaTeX pages + 5 ps figure
Two-photon correlations as a sign of sharp transition in quark-gluon plasma
The photon production arising due to time variation of the medium has been
considered. The Hamilton formalism for photons in time-variable medium (plasma)
has been developed with application to inclusive photon production. The results
have been used for calculation of the photon production in the course of
transition from quark-gluon phase to hadronic phase in relativistic heavy ion
collisions. The relative strength of the effect as well as specific two- photon
correlations have been evaluated. It has been demonstrated that the opposite
side two-photon correlations are indicative of the sharp transition from the
quark-gluon phase to hadrons.Comment: 23 pages, 2 figure
Re-entrant localization of single particle transport in disordered Andreev wires
We study effects of disorder on the low energy single particle transport in a
normal wire surrounded by a superconductor. We show that the heat conductance
includes the Andreev diffusion decreasing with increase in the mean free path
and the diffusive drift produced by a small particle-hole asymmetry,
which increases with increasing . The conductance thus has a minimum as a
function of which leads to a peculiar re-entrant localization as a
function of the mean free path.Comment: 4 pages, 2 figure
Plasmon-mediated superradiance near metal nanostructures
We develop a theory of cooperative emission of light by an ensemble of
emitters, such as fluorescing molecules or semiconductor quantum dots, located
near a metal nanostructure supporting surface plasmon. The primary mechanism of
cooperative emission in such systems is resonant energy transfer between
emitters and plasmons rather than the Dicke radiative coupling between
emitters. We identify two types of plasmonic coupling between the emitters, (i)
plasmon-enhanced radiative coupling and (ii) plasmon-assisted nonradiative
energy transfer, the competition between them governing the structure of system
eigenstates. Specifically, when emitters are removed by more than several nm
from the metal surface, the emission is dominated by three superradiant states
with the same quantum yield as a single emitter, resulting in a drastic
reduction of ensemble radiated energy, while at smaller distances cooperative
behavior is destroyed by nonradiative transitions. The crossover between two
regimes can be observed in distance dependence of ensemble quantum efficiency.
Our numerical calculations incorporating direct and plasmon-assisted
interactions between the emitters indicate that they do not destroy the
plasmonic Dicke effect.Comment: 12 pages, 10 figure
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