167 research outputs found
Three level atom optics in dipole traps and waveguides
An analogy is explored between a setup of three atomic traps coupled via
tunneling and an internal atomic three-level system interacting with two laser
fields. Within this scenario we describe a STIRAP like process which allows to
move an atom between the ground states of two trapping potentials and analyze
its robustness. This analogy is extended to other robust and coherent transport
schemes and to systems of more than a single atom. Finally it is applied to
manipulate external degrees of freedom of atomic wave packets propagating in
waveguides.Comment: 14 pages, 6 figures; submitted to special issue 'Quantum Control of
Light and Matter' of Optics Communication
Generation of entangled photon pairs in optical cavity-QED: Operating in the bad cavity limit
We propose an optical cavity-QED scheme for the deterministic generation of
polarization entangled photon pairs that operates with high fidelity even in
the bad cavity limit. The scheme is based on the interaction of an excited
four-level atom with two empty optical cavity modes via an adiabatic passage
process. Monte-Carlo wave function simulations are used to evaluate the
fidelity of the cavity-QED source and its entanglement capability in the
presence of decoherence. In the bad cavity limit, fidelities close to one are
predicted for state-of-the-art experimental parameter values.Comment: 9 pages and 5 figure
Single atom edge-like states via quantum interference
We demonstrate how quantum interference may lead to the appearance of robust
edge-like states of a single ultracold atom in a two-dimensional optical
ribbon. We show that these states can be engineered either within the manifold
of local ground states of the sites forming the ribbon, or of states carrying
one unit of angular momentum. In the former case, we show that the
implementation of edge-like states can be extended to other geometries, such as
tilted square lattices. In the latter case, we suggest to use the winding
number associated to the angular momentum as a synthetic dimension.Comment: 5 pages, 5 figure
Wave-vector and polarization dependence of conical refraction
We experimentally address the wave-vector and polarization dependence of the
internal conical refraction phenomenon by demonstrating that an input light
beam of elliptical transverse profile refracts into two beams after passing
along one of the optic axes of a biaxial crystal, i.e. it exhibits double
refraction instead of refracting conically. Such double refraction is
investigated by the independent rotation of a linear polarizer and a
cylindrical lens. Expressions to describe the position and the intensity
pattern of the refracted beams are presented and applied to predict the
intensity pattern for an axicon beam propagating along the optic axis of a
biaxial crystal
Optical vault: reconfigurable bottle beam by conically refracted light
We employ conical refraction of light in a biaxial crystal to create an
optical bottle for trapping and manipulation of particles. We show that by just
varying the polarization of the input light the bottle can be opened and closed
at will. We experimentally demonstrate stable photophoretic trapping and
controllable loading and unloading of light absorbing particles in the trap.Comment: 4 pages, 5 figure
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