We propose and analyze a scheme by which a many-particle system can be prepared in highly entangled wave-packet states. One of the particles is prepared initially in a quantum superposition of multiple coherent states and then coupled via a quadratic interaction Hamiltonian to a number of other particles. The system evolves into a highly entangled wave-packet state. An appropriate measure of this time-dependent entanglement is given. This scheme is applicable to a number of systems of interest in quantum-information science.

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At the Air Force Research Laboratory's Space Vehicles Directorate, we are investigating how nanostructured metal surfaces can produce plasmon-enhanced fields to improve detectivity of a detector material placed directly below the metal surface. We are also investigating a wavelength-tunable detector scheme that involves a coupled double quantum well structure with a thin middle barrier between the two wells. The photocurrent from this structure will be swept out with a lateral bias. Another form of wavelength tunability is to have a tunable filter in front of a broadband detector. There are many avenues of research that lead to such a device. The way we are approaching this is via the new field of metamaterials. Not only might these new materials present us a way to tune the light that is incident upon a detector, but such research might also lead to ways to obtain sub-diffraction-limit resolution and the concentration of light using flat lenses for increased signal-to-noise ratios. In this talk we will discuss the research efforts being pursued in the above areas.

We explicitly calculate the time dependence of entanglement via the convex roof extension for a system of noninteracting harmonic oscillators. These oscillators interact only indirectly with each other by way of a zero-temperature bath. The initial state of the oscillators is taken to be that of an entangled Schrödinger-cat state. This type of initial condition leads to superexponential decay of the entanglement when the initial state has the same symmetry as the interaction Hamiltonian.

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