143,054 research outputs found
Entangling two atoms in spatially separated cavities through both photon emission and absorption processes
Get PDFWe consider a system consisting of a -type atom and a V-type atom,
which are individually trapped in two spatially separated cavities that are
connected by an optical fibre. We show that an extremely entangled state of the
two atoms can be deterministically generated through both photon emission of
the -type atom and photon absorption of the V-type atom in an ideal
situation. The influence of various decoherence processes such as spontaneous
emission and photon loss on the fidelity of the entangled state is also
investigated. We find that the effect of photon leakage out of the fibre on the
fidelity can be greatly diminished in some special cases. As regards the effect
of spontaneous emission and photon loss from the cavities, we find that the
present scheme with a fidelity higher than 0.98 may be realized under current
experiment conditions.Comment: 12 pages, 4 figure
Green's Function of 3-D Helmholtz Equation for Turbulent Medium: Application to Optics
Full text linkThe fundamental problem of optical wave propagation is the determination of
the field at an observation point, given a disturbance specified over some
finite aperture. In both vacuum and inhomogeneous media, the solution of this
problem is given approximately by the superposition integral, which is a
mathematical expression of the extended Huygens-Fresnel principle. In doing so,
it is important to find the atmospheric impulse response (Green's function).
Within a limited but useful region of validity, a satisfactory optical
propagation theory for the earth's clear turbulent atmosphere could be
developed by using Rytov's method to approximate the Helmholtz equation. In
particular, we deal with two optical problems which are the time reversal and
apodization problems. The background and consequences of these results for
optical communication through the atmosphere are briefly discussed
- …
