2,837 research outputs found
Bilinear and quadratic Hamiltonians in two-mode cavity quantum electrodynamics
In this work we show how to engineer bilinear and quadratic Hamiltonians in
cavity quantum electrodynamics (QED) through the interaction of a single driven
two-level atom with cavity modes. The validity of the engineered Hamiltonians
is numerically analyzed even considering the effects of both dissipative
mechanisms, the cavity field and the atom. The present scheme can be used, in
both optical and microwave regimes, for quantum state preparation, the
implementation of quantum logical operations, and fundamental tests of quantum
theory.Comment: 11 pages, 3 figure
Time-gated transillumination and reflection by biological tissues and tissuelike phantoms: simulation versus experiment
A numerical method is presented to solve exactly the time-dependent diffusion equation that describes light transport in turbid media. The simulation takes into account spatial variations of the scattering and absorption factors of the medium and the objects as well as random fluctuations of these quantities. The technique is employed to explore the possibility of locating millimeter-sized objects immersed in turbid media from time-gated measurements of the transmitted or reflected (near-infrared) light. The simulation results for tissue-like phantoms are compared with experimental transillumination data, and excellent agreement is found. Simulations of time-gated reflection experiments indicate that it may be possible to detect objects of 1-mm radius.
Beeswax foundations with impregnated thymol for Varroa control
The use of essential oils and organic acids is generally
accepted as an alternative tool for the control of the
Varroa Destructor levels in bee's colonies, avoiding mite
resistance and reducing the residues contaminations
resulting from the systematic application of synthetic
chemicals
Nonadiabatic coherent evolution of two-level systems under spontaneous decay
In this paper we extend current perspectives in engineering reservoirs by
producing a time-dependent master equation leading to a nonstationary
superposition equilibrium state that can be nonadiabatically controlled by the
system-reservoir parameters. Working with an ion trapped inside a nonindeal
cavity we first engineer effective Hamiltonians that couple the electronic
states of the ion with the cavity mode. Subsequently, two classes of
decoherence-free evolution of the superposition of the ground and decaying
excited levels are achieved: those with time-dependent azimuthal or polar
angle. As an application, we generalise the purpose of an earlier study [Phys.
Rev. Lett. 96, 150403 (2006)], showing how to observe the geometric phases
acquired by the protected nonstationary states even under a nonadiabatic
evolution.Comment: 5 pages, no figure
Time-Resolved Diffusing Wave Spectroscopy for selected photon paths beyond 300 transport mean free paths
This paper is devoted to the theoretical and experimental demonstration of
the possibility to perform time-resolved diffusing wave spectroscopy: we
successfully registered field fluctuations for selected photon path lengths
that can overpass 300 transport mean free paths. Such a performance opens new
possibilities for biomedical optics applications.Comment: 12 pages, 3 figure
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