5,225 research outputs found
Quantum Teleportation of Light
Requirements for the successful teleportation of a beam of light, including
its temporal correlations, are discussed. Explicit expressions for the degrees
of first- and second-order optical coherence are derived. Teleportation of an
antibunched photon stream illustrates our results.Comment: 4 pages, 5 figure
Defect Formation and Kinetics of Atomic Terrace Merging
Pairs of atomic scale terraces on a single crystal metal surface can be made
to merge controllably under suitable conditions to yield steps of double height
and width. We study the effect of various physical parameters on the formation
of defects in a kinetic model of step doubling. We treat this manifestly non-
equilibrium problem by mapping the model onto a 1-D random sequential
adsorption problem and solving this analytically. We also do simulations to
check the validity of our treatment. We find that our treatment effectively
captures the dynamic evolution and the final state of the surface morphology.
We show that the number and nature of the defects formed is controlled by a
single dimensionless parameter . For close to one we show that the
fraction of defects rises linearly with as . We also show that one can arrive at the final state faster and with
fewer defects by changing the parameter with time.Comment: 17 pages, 8 figures. To be submitted to Phys. Rev.
Preroughening transitions in a model for Si and Ge (001) type crystal surfaces
The uniaxial structure of Si and Ge (001) facets leads to nontrivial
topological properties of steps and hence to interesting equilibrium phase
transitions. The disordered flat phase and the preroughening transition can be
stabilized without the need for step-step interactions. A model describing this
is studied numerically by transfer matrix type finite-size-scaling of interface
free energies. Its phase diagram contains a flat, rough, and disordered flat
phase, separated by roughening and preroughening transition lines. Our estimate
for the location of the multicritical point where the preroughening line merges
with the roughening line, predicts that Si and Ge (001) undergo preroughening
induced simultaneous deconstruction transitions.Comment: 13 pages, RevTex, 7 Postscript Figures, submitted to J. Phys.
Work distribution for the driven harmonic oscillator with time-dependent strength: Exact solution and slow driving
We study the work distribution of a single particle moving in a harmonic
oscillator with time-dependent strength. This simple system has a non-Gaussian
work distribution with exponential tails. The time evolution of the
corresponding moment generating function is given by two coupled ordinary
differential equations that are solved numerically. Based on this result we
study the behavior of the work distribution in the limit of slow but finite
driving and show that it approaches a Gaussian distribution arbitrarily well
Frictional Drag between Two Dilute Two-Dimensional Hole Layers
We report drag measurements on dilute double layer two-dimensional hole
systems in the regime of r_s=19~39. We observed a strong enhancement of the
drag over the simple Boltzmann calculations of Coulomb interaction, and
deviations from the T^2 dependence which cannot be explained by
phonon-mediated, plasmon-enhanced, or disorder-related processes. We suggest
that this deviation results from interaction effects in the dilute regime.Comment: 4 pages, 3 figures, accepted in Phys. Rev. Lett. Added single layer
transport dat
Phenomenology of ageing in the Kardar-Parisi-Zhang equation
We study ageing during surface growth processes described by the
one-dimensional Kardar-Parisi-Zhang equation. Starting from a flat initial
state, the systems undergo simple ageing in both correlators and linear
responses and its dynamical scaling is characterised by the ageing exponents
a=-1/3, b=-2/3, lambda_C=lambda_R=1 and z=3/2. The form of the autoresponse
scaling function is well described by the recently constructed logarithmic
extension of local scale-invariance.Comment: Latex2e, 5 pages, with 4 figures, final for
Extended Universality of the Surface Curvature in Equilibrium Crystal Shapes
We investigate the universal property of curvatures in surface models which
display a flat phase and a rough phase whose criticality is described by the
Gaussian model. Earlier we derived a relation between the Hessian of the free
energy and the Gaussian coupling constant in the six-vertex model. Here we show
its validity in a general setting using renormalization group arguments. The
general validity of the relation is confirmed numerically in the RSOS model by
comparing the Hessian of the free energy and the Gaussian coupling constant in
a transfer matrix finite-size-scaling study. The Hessian relation gives clear
understanding of the universal curvature jump at roughening transitions and
facet edges and also provides an efficient way of locating the phase
boundaries.Comment: 19 pages, RevTex, 3 Postscript Figures, To appear in Phys. Rev.
Photoluminescence modification by high-order photonic band with abnormal dispersion in ZnO inverse opal
We measured the angle- and polarization-resolved reflection and
photoluminescence spectra of ZnO inverse opals. Significant enhancement of
spontaneous emission is observed. The enhanced emission not only has good
directionality but also can be linearly polarized. A detailed theoretical
analysis and numerical simulation reveal that such enhancement is caused by the
abnormal dispersion of a high-order photonic band. The frozen mode at a
stationary inflection point of a dispersion curve can strongly modify the
intensity, directionality and polarization of spontaneous emission.Comment: 22 pages, 11 figures, figures modified, references added, more
explanation adde
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