Nanodot-Cavity Electrodynamics and Photon Entanglement

Quantum electrodynamics of excitons in a cavity is shown to be relevant to quantum operations. We present a theory of an integrable solid-state quantum controlled-phase gate for generating entanglement of two photons using a coupled nanodot-microcavity-fiber structure. A conditional phase shift of $O(\pi/10)$ is calculated to be the consequence of the giant optical nonlinearity keyed by the excitons in the cavities. Structural design and active control, such as electromagnetic induced transparency and pulse shaping, optimize the quantum efficiency of the gate operation.Comment: 4 pages 3 figure

Relativistic diffusion of elementary particles with spin

We obtain a generalization of the relativistic diffusion of Schay and Dudley for particles with spin. The diffusion equation is a classical version of an equation for the Wigner function of an elementary particle. The elementary particle is described by a unitary irreducible representation of the Poincare group realized in the Hilbert space of wave functions in the momentum space. The arbitrariness of the Wigner rotation appears as a gauge freedom of the diffusion equation. The spin is described as a connection of a fiber bundle over the momentum hyperbolic space (the mass-shell). Motion in an electromagnetic field, transport equations and equilibrium states are discussed.Comment: 21 pages,minor changes,the version published in Journ.Phys.

Event-by-event Simulation of Quantum Cryptography Protocols

We present a new approach to simulate quantum cryptography protocols using event-based processes. The method is validated by simulating the BB84 protocol and the Ekert protocol, both without and with the presence of an eavesdropper

Beyond the Parton Cascade Model: Klaus Kinder-Geiger and VNI

I review Klaus Kinder-Geiger's contributions to the physics of relativistic heavy ion collisions, in particular, the Parton Cascade Model. Klaus developed this model in order to provide a QCD-based description of nucleus-nucleus reactions at high energies such as they will soon become available at the Brookhaven Relativistic Heavy Ion Collider. The PCM describes the collision dynamics within the early and dense phase of the reaction in terms of the relativistic, probabilistic transport of perturbative excitations (partons) of the QCD vacuum. I will present an overview of the current state of the numerical implementations of this model, as well as its predictions for nuclear collisions at RHIC and LHC.Comment: Talk given at the "KKG-Day" Workshop, Brookhaven National Laboratory, October 23, 1998. 17 pages, 5 figure