16,734 research outputs found
Mutants and SU(3)_q invariants
Details of quantum knot invariant calculations using a specific
SU(3)_q-module are given which distinguish the Conway and Kinoshita-Teresaka
pair of mutant knots. Features of Kuperberg's skein-theoretic techniques for
SU(3)_q invariants in the context of mutant knots are also discussed.Comment: 17 pages. Published copy, also available at
http://www.maths.warwick.ac.uk/gt/GTMon1/paper18.abs.htm
The Role of Tree Clinics in Urban Forestry
A tree clinic analyzes tree problems and recommends appropriate actions to the public. The objective of tree clinics is to inform the citizen about urban trees. This paper is based on the experiences of 30 tree clinics held in Ann Arbor during the last eight years. The ingredients necessary for a successful tree clinic are discussed: (I) active sponsor, (2) suitable date and time, (3) good location, (4) proper publicity, (5) diversified experts, (6) proper organization, (7) sizable public turnout, and (8) follow-up publicity and acknowledgments
Developing Country Debt and Economic Performance, Volume 1: The International Financial System
Deligne-Beilinson cohomology and abelian link invariants: torsion case
For the abelian Chern-Simons field theory, we consider the quantum functional
integration over the Deligne-Beilinson cohomology classes and present an
explicit path-integral non-perturbative computation of the Chern-Simons link
invariants in , a toy example of 3-manifold with
torsion
Numerical analysis of the Iosipescu specimen for composite materials
A finite element analysis of the Iosipescu shear tests for unidirectional and cross-ply composites is presented. It is shown that an iterative analysis procedure must be used to model the fixture-specimen kinematics. The correction factors which are needed to compensate for the nonuniformity of stress distribution in calculating shear modulus are shown to be dependent on the material orthotropic ratio and the finite element loading models. Test section strain distributions representative of typical graphite-epoxy specimens are also presented
Quantum computing with an electron spin ensemble
We propose to encode a register of quantum bits in different collective
electron spin wave excitations in a solid medium. Coupling to spins is enabled
by locating them in the vicinity of a superconducting transmission line cavity,
and making use of their strong collective coupling to the quantized radiation
field. The transformation between different spin waves is achieved by applying
gradient magnetic fields across the sample, while a Cooper Pair Box, resonant
with the cavity field, may be used to carry out one- and two-qubit gate
operations.Comment: Several small corrections and modifications. This version is
identical to the version published in Phys. Rev. Let
Two-Photon Beatings Using Biphotons Generated from a Two-Level System
We propose a two-photon beating experiment based upon biphotons generated
from a resonant pumping two-level system operating in a backward geometry. On
the one hand, the linear optical-response leads biphotons produced from two
sidebands in the Mollow triplet to propagate with tunable refractive indices,
while the central-component propagates with unity refractive index. The
relative phase difference due to different refractive indices is analogous to
the pathway-length difference between long-long and short-short in the original
Franson interferometer. By subtracting the linear Rayleigh scattering of the
pump, the visibility in the center part of the two-photon beating interference
can be ideally manipulated among [0, 100%] by varying the pump power, the
material length, and the atomic density, which indicates a Bell-type inequality
violation. On the other hand, the proposed experiment may be an interesting way
of probing the quantum nature of the detection process. The interference will
disappear when the separation of the Mollow peaks approaches the fundamental
timescales for photon absorption in the detector.Comment: to appear in Phys. Rev. A (2008
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