35,869 research outputs found
Phase Space Reduction for Star-Products: An Explicit Construction for CP^n
We derive a closed formula for a star-product on complex projective space and
on the domain using a completely elementary
construction: Starting from the standard star-product of Wick type on and performing a quantum analogue of Marsden-Weinstein
reduction, we can give an easy algebraic description of this star-product.
Moreover, going over to a modified star-product on ,
obtained by an equivalence transformation, this description can be even further
simplified, allowing the explicit computation of a closed formula for the
star-product on \CP^n which can easily transferred to the domain
.Comment: LaTeX, 17 page
Finite Cluster Typical Medium Theory for Disordered Electronic Systems
We use the recently developed typical medium dynamical cluster (TMDCA)
approach~[Ekuma \etal,~\textit{Phys. Rev. B \textbf{89}, 081107 (2014)}] to
perform a detailed study of the Anderson localization transition in three
dimensions for the Box, Gaussian, Lorentzian, and Binary disorder
distributions, and benchmark them with exact numerical results. Utilizing the
nonlocal hybridization function and the momentum resolved typical spectra to
characterize the localization transition in three dimensions, we demonstrate
the importance of both spatial correlations and a typical environment for the
proper characterization of the localization transition in all the disorder
distributions studied. As a function of increasing cluster size, the TMDCA
systematically recovers the re-entrance behavior of the mobility edge for
disorder distributions with finite variance, obtaining the correct critical
disorder strengths, and shows that the order parameter critical exponent for
the Anderson localization transition is universal. The TMDCA is computationally
efficient, requiring only a small cluster to obtain qualitative and
quantitative data in good agreement with numerical exact results at a fraction
of the computational cost. Our results demonstrate that the TMDCA provides a
consistent and systematic description of the Anderson localization transition.Comment: 20 Pages, 19 Figures, 3 Table
Entanglement of two qubits mediated by one-dimensional plasmonic waveguides
We investigate qubit-qubit entanglement mediated by plasmons supported by
one-dimensional waveguides. We explore both the situation of spontaneous
formation of entanglement from an unentangled state and the emergence of driven
steady-state entanglement under continuous pumping. In both cases, we show that
large values for the concurrence are attainable for qubit-qubit distances
larger than the operating wavelength by using plasmonic waveguides that are
currently available.Comment: 4 pages, 4 figures. Minor Changes. Journal Reference added.
Highlighted in Physic
Multimode interference devices for focusing in microfluidic channels
Low-cost, compact, automated optical microsystems for chemical analysis, such as microflow cytometers for identification of individual biological cells, require monolithically integrated microlenses for focusing in microfluidic channels, to enable high-resolution scattering and fluorescence measurements. The multimode interference device (MMI), which makes use of self-imaging in multimode waveguides, is shown to be a simple and effective alternative to the microlens for microflow cytometry. The MMIs have been designed, realized, and integrated with microfluidic channels in a silica-based glass waveguide material system. Focal spot sizes of 2.4 ”m for MMIs have been measured at foci as far as 43.7 ”m into the microfluidic channel
Errors on the inverse problem solution for a noisy spherical gravitational wave antenna
A single spherical antenna is capable of measuring the direction and
polarization of a gravitational wave. It is possible to solve the inverse
problem using only linear algebra even in the presence of noise. The simplicity
of this solution enables one to explore the error on the solution using
standard techniques. In this paper we derive the error on the direction and
polarization measurements of a gravitational wave. We show that the solid angle
error and the uncertainty on the wave amplitude are direction independent. We
also discuss the possibility of determining the polarization amplitudes with
isotropic sensitivity for any given gravitational wave source.Comment: 13 pages, 4 figures, LaTeX2e, IOP style, submitted to CQ
Synchronizability determined by coupling strengths and topology on Complex Networks
We investigate in depth the synchronization of coupled oscillators on top of
complex networks with different degrees of heterogeneity within the context of
the Kuramoto model. In a previous paper [Phys. Rev. Lett. 98, 034101 (2007)],
we unveiled how for fixed coupling strengths local patterns of synchronization
emerge differently in homogeneous and heterogeneous complex networks. Here, we
provide more evidence on this phenomenon extending the previous work to
networks that interpolate between homogeneous and heterogeneous topologies. We
also present new details on the path towards synchronization for the evolution
of clustering in the synchronized patterns. Finally, we investigate the
synchronization of networks with modular structure and conclude that, in these
cases, local synchronization is first attained at the most internal level of
organization of modules, progressively evolving to the outer levels as the
coupling constant is increased. The present work introduces new parameters that
are proved to be useful for the characterization of synchronization phenomena
in complex networks.Comment: 11 pages, 10 figures and 1 table. APS forma
Metal-Insulator-Transition in a Weakly interacting Disordered Electron System
The interplay of interactions and disorder is studied using the
Anderson-Hubbard model within the typical medium dynamical cluster
approximation. Treating the interacting, non-local cluster self-energy
() up to second order in the
perturbation expansion of interactions, , with a systematic incorporation
of non-local spatial correlations and diagonal disorder, we explore the initial
effects of electron interactions () in three dimensions. We find that the
critical disorder strength (), required to localize all states,
increases with increasing ; implying that the metallic phase is stabilized
by interactions. Using our results, we predict a soft pseudogap at the
intermediate close to and demonstrate that the mobility edge
() is preserved as long as the chemical potential, , is
at or beyond the mobility edge energy.Comment: 10 Pages, 8 Figures with Supplementary materials include
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