19,498 research outputs found
Extreme sub-wavelength atom localization via coherent population trapping
We demonstrate an atom localization scheme based on monitoring of the atomic
coherences. We consider atomic transitions in a Lambda configuration where the
control field is a standing wave field. The probe field and the control field
produce coherence between the two ground states. We show that this coherence
has the same fringe pattern as produced by a Fabry-Perot interferometer and
thus measurement of the atomic coherence would localize the atom. Interestingly
enough the role of the cavity finesse is played by the ratio of the intensities
of the pump and probe. This is in fact the reason for obtaining extreme
subwavelenth localization. We suggest several methods to monitor the produced
localization.Comment: 6 pages, 5 figure
Numerical investigation of unsteady laminar incompressible co-axial boundary layer flows
Finite difference method for analysis of laminar incompressible boundary layer flows at jet exi
Tunable Entanglement, Antibunching and Saturation effects in Dipole Blockade
We report a model that makes it possible to analyze quantitatively the dipole
blockade effect on the dynamical evolution of a two two-level atom system
driven by an external laser field. The multiple excitations of the atomic
sample are taken into account. We find very large concurrence in the dipole
blockade regime. We further find that entanglement can be tuned by changing the
intensity of the exciting laser. We also report a way to lift the dipole
blockade paving the way to manipulate in a controllable way the blockade
effects. We finally report how a continuous monitoring of the dipole blockade
would be possible using photon-photon correlations of the scattered light in a
regime where the spontaneous emission would dominate dissipation in the sample.Comment: 5 pages, 5 figure
Comparing the prime and subprime mortgage markets
Against the backdrop of news reports on high mortgage delinquency rates, this article examines recent trends in mortgage lending and compares the prime and subprime markets in particular.Mortgages
Generation of Symmetric Dicke States of Remote Qubits with Linear Optics
We propose a method for generating all symmetric Dicke states, either in the
long-lived internal levels of N massive particles or in the polarization
degrees of freedom of photonic qubits, using linear optical tools only. By
means of a suitable multiphoton detection technique, erasing Welcher-Weg
information, our proposed scheme allows the generation and measurement of an
important class of entangled multiqubit states.Comment: New version, a few modifications and a new figure, accepted in
Physical Review Letter
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