29,209 research outputs found
SU(5) Heterotic Standard Model Bundles
We construct a class of stable SU(5) bundles on an elliptically fibered
Calabi-Yau threefold with two sections, a variant of the ordinary Weierstrass
fibration, which admits a free involution. The bundles are invariant under the
involution, solve the topological constraint imposed by the heterotic anomaly
equation and give three generations of Standard Model fermions after symmetry
breaking by Wilson lines of the intermediate SU(5) GUT-group to the Standard
Model gauge group. Among the solutions we find some which can be perturbed to
solutions of the Strominger system. Thus these solutions provide a step toward
the construction of phenomenologically realistic heterotic flux
compactifications via non-Kahler deformations of Calabi-Yau geometries with
bundles. This particular class of solutions involves a rank two hidden sector
bundle and does not require background fivebranes for anomaly cancellation.Comment: 17 page
Measurable nonlocal effect of bipartite system during a local cyclic evolution of its subsystem
In this letter, a nonlocal effect for a bipartite system which is induced by
a local cyclic evolution of one of its subsystem is suggested. This effect
vanishes when the system is at a disentangled pure state but can be observed
for some disentangled mixed states. As a paradigm, we study the effect for the
system of two qubits in detail. It is interesting that the effect is directly
related to the degree of entanglement for pure state of qubit pairs.
Furthermore, we suggest a Bell-type experiment to measure this nonlocal effect
for qubit pairs.Comment: 5 pages, 2 figure
csi2p modulates microtubule dynamics and organizes the bipolar spindle for chromosome segregation
published_or_final_versio
Schmidt number of pure bi-partite entangled states and methods of its calculation
An entanglement measure for pure-state continuous-variable bi-partite
problem, the Schmidt number, is analytically calculated for one simple model of
atom-field scattering.Comment: 3 pages, 1 figure; based on the poster presentation reported on the
11th International Conference on Quantum Optics (ICQO'2006, Minsk, May 26 --
31, 2006), to be published in special issue of Optics and Spectroscop
Metamaterial with polarization and direction insensitive resonant transmission response mimicking electromagnetically induced transparency
We report on a planar metamaterial, the resonant transmission frequency of which does not depend on the polarization and angle of incidence of electromagnetic waves. The resonance results from the excitation of high-Q antisymmetric trapped current mode and shows sharp phase dispersion characteristic to Fano-type resonances of the electromagnetically induced transparency phenomenon
Topological properties of superconducting junctions
Motivated by recent developments in the field of one-dimensional topological
superconductors, we investigate the topological properties of s-matrix of
generic superconducting junctions where dimension should not play any role. We
argue that for a finite junction the s-matrix is always topologically trivial.
We resolve an apparent contradiction with the previous results by taking into
account the low-energy resonant poles of s-matrix. Thus no common topological
transition occur in a finite junction. We reveal a transition of a different
kind that concerns the configuration of the resonant poles
Influence of the trap shape on the superfluid-Mott transition in ultracold atomic gases
The coexistence of superfluid and Mott insulator, due to the quadratic
confinement potential in current optical lattice experiments, makes the
accurate detection of the superfluid-Mott transition difficult. Studying
alternative trapping potentials which are experimentally realizable and have a
flatter center, we find that the transition can be better resolved, but at the
cost of a more difficult tuning of the particle filling. When mapping out the
phase diagram using local probes and the local density approximation we find
that the smoother gradient of the parabolic trap is advantageous.Comment: 5 pages, 6 figure
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