943 research outputs found
RoundTripRank: Graph-based Proximity with Importance and Specificity
Advanced Digital Sciences Center of the University of Illinois at Urbana-Champaign, Agency for Science, Technology and Research of Singapor
Repeat-Until-Success quantum computing using stationary and flying qubits
We introduce an architecture for robust and scalable quantum computation
using both stationary qubits (e.g. single photon sources made out of trapped
atoms, molecules, ions, quantum dots, or defect centers in solids) and flying
qubits (e.g. photons). Our scheme solves some of the most pressing problems in
existing non-hybrid proposals, which include the difficulty of scaling
conventional stationary qubit approaches, and the lack of practical means for
storing single photons in linear optics setups. We combine elements of two
previous proposals for distributed quantum computing, namely the efficient
photon-loss tolerant build up of cluster states by Barrett and Kok [Phys. Rev.
A 71, 060310(R) (2005)] with the idea of Repeat-Until-Success (RUS) quantum
computing by Lim et al. [Phys. Rev. Lett. 95, 030505 (2005)]. This idea can be
used to perform eventually deterministic two-qubit logic gates on spatially
separated stationary qubits via photon pair measurements. Under non-ideal
conditions, where photon loss is a possibility, the resulting gates can still
be used to build graph states for one-way quantum computing. In this paper, we
describe the RUS method, present possible experimental realizations, and
analyse the generation of graph states.Comment: 14 pages, 7 figures, minor changes, references and a discussion on
the effect of photon dark counts adde
Heterogeneous embedding propagation for large-scale e-commerce user alignment
National Research Foundation (NRF) Singapore CREATE; Alibaba Innovative Researc
Rare B decays and Tevatron top-pair asymmetry
The recent Tevatron result on the top quark forward-backward asymmetry, which
deviates from its standard model prediction by 3.4, has prompted many
authors to build new models to account for this anomaly. Among the various
proposals, we find that those mechanisms which produce via - or
-channel can have a strong correlation to the rare B decays. We demonstrate
this link by studying a model with a new charged gauge boson, . In terms of
the current measurements on decays, we conclude that the branching
ratio for is affected most by the new effects.
Furthermore, using the world average branching ratio for the exclusive B decays
at level, we discuss the allowed values for the new parameters.
Finally, we point out that the influence of the new physics effects on the
direct CP asymmetry in B decays is insignificant.Comment: 15 page, 6 figures, typos corrected and references added, final
version to appear journa
Conformal Affine Toda Soliton and Moduli of IIB Superstring on
In this paper we interpret the hidden symmetry of the moduli space of IIB
superstring on in terms of the chiral embedding in
, which turns to be the conformal affine Toda model.
We review how the position of poles in the Riemann-Hilbert formulation
of dressing transformation and how the value of loop parameters in the
vertex operator of affine algebra determines the moduli space of the soliton
solutions, which describes the moduli space of the Green-Schwarz superstring.
We show also how this affine SU(4) symmetry affinize the conformal symmetry in
the twistor space, and how a soliton string corresponds to a Robinson
congruence with twist and dilation spin coefficients of twistor.Comment: Final version, Misprints corrected, Note adde
Baryonium, tetra-quark state and glue-ball in large N_c QCD
From the large-N_c QCD point of view, baryonia, tetra-quark states, hybrids,
and glueballs are studied. The existence of these states is argued for. They
are constructed from baryons. In N_f=1 large N_c QCD, a baryonium is always
identical to a glueball with N_c valence gluons. The ground state 0^{-+}
glueball has a mass about 2450 MeV. f_0(1710) is identified as the lowest
0^{++} glueball. The lowest four-quark nonet should be f_0(1370), a_0(1450),
K^*_0(1430) and f_0(1500). Combining with the heavy quark effective theory,
spectra of heavy baryonia and heavy tetra-quark states are predicted. 1/N_c
corrections are discussed.Comment: 16 pages, 3 figure
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