5 research outputs found
Improvement by laser quenching of an "atom diode": a one-way barrier for ultra-cold atoms
Different laser devices working as ``atom diodes'' or ``one-way barriers''
for ultra-cold atoms have been proposed recently. They transmit ground state
level atoms coming from one side, say from the left, but reflect them when they
come from the other side. We combine a previous model, consisting of the
stimulated Raman adiabatic passage (STIRAP) from the ground to an excited state
and a state-selective mirror potential, with a localized quenching laser which
produces spontaneous decay back to the ground state. This avoids backwards
motion, provides more control of the decay process and therefore a more compact
and useful device.Comment: 6 page
Optimal atomic detection by control of detuning and spatial dependence of laser intensity
Atomic detection by fluorescence may fail because of reflection from the
laser or transmission without excitation. The detection probability for a given
velocity range may be improved by controlling the detuning and the spatial
dependence of the laser intensity. A simple optimization method is discussed
and exemplified
Quantum optical time-of-arrival model in three dimensions
We investigate the three-dimensional formulation of a recently proposed
operational arrival-time model. It is shown that within typical conditions for
optical transitions the results of the simple one-dimensional version are
generally valid. Differences that may occur are consequences of Doppler and
momentum-transfer effects. Ways to minimize these are discussed.Comment: 14 pages, 5 figure
Scattering of two-level atoms by delta lasers: Exactly solvable models in atom optics
We study the scattering of two-level atoms at narrow laser fields, modeled by
a -shape intensity profile. The unique properties of these potentials
allow us to give simple analytic solutions for one or two field zones. Several
applications are studied: a single -laser may serve as a detector model
for atom detection and arrival-time measurements, either by means of
fluorescence or variations in occupation probabilities. We show that, in
principle, this ideal detector can measure the particle density, the quantum
mechanical flux, arrival time distributions or local kinetic energy densities.
Moreover, two spatially separated -lasers are used to investigate
quantized-motion effects on Ramsey interferometry.Comment: 11 pages, 5 figure