15,343 research outputs found
Improving the Fidelity of Optical Zeno Gates via Distillation
We have modelled the Zeno effect Control-Sign gate of Franson et al (PRA 70,
062302, 2004) and shown that high two-photon to one-photon absorption ratios,
, are needed for high fidelity free standing operation. Hence we
instead employ this gate for cluster state fusion, where the requirement for
is less restrictive. With the help of partially offline one-photon and
two-photon distillations, we can achieve a fusion gate with unity fidelity but
non-unit probability of success. We conclude that for , the Zeno
fusion gate will out perform the equivalent linear optics gate.Comment: 6 pages, 11 figures, Submitted to PR
Properties of a magnetic superconductor with weak magnetization - application to
Using a Ginsburg-Landau free energy functional, we study the phase
diagram of a weak magnetic superconductor, where the magnetization from the
magnetic component is marginal in supporting a spontaneous vortex phase in
absence of external magnetic field. In particular, the competition between the
spiral state and spontaneous vortex phase is analysed. Our theory is applied to
understand the magnetic properties of .Comment: 13 pages, 4 postscript figure
Finding Faces in Cluttered Scenes using Random Labeled Graph Matching
An algorithm for locating quasi-frontal views of human faces in cluttered scenes is presented. The algorithm works by coupling a set of local feature detectors with a statistical model of the mutual distances between facial features it is invariant with respect to translation, rotation (in the plane), and scale and can handle partial occlusions of the face. On a challenging database with complicated and varied backgrounds, the algorithm achieved a correct localization rate of 95% in images where the face appeared quasi-frontally
Novel Phases and Finite-Size Scaling in Two-Species Asymmetric Diffusive Processes
We study a stochastic lattice gas of particles undergoing asymmetric
diffusion in two dimensions. Transitions between a low-density uniform phase
and high-density non-uniform phases characterized by localized or extended
structure are found. We develop a mean-field theory which relates
coarse-grained parameters to microscopic ones. Detailed predictions for
finite-size () scaling and density profiles agree excellently with
simulations. Unusual large- behavior of the transition point parallel to
that of self-organized sandpile models is found.Comment: 7 pages, plus 6 figures uuencoded, compressed and appended after
source code, LATeX, to be published as a Phys. Rev. Let
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