aktualisiertes pdf - DPG-Tagungen

tierte Atomen/sec mit einer Kollimation besser als 0.5vrecoil. Die örtliche
Auflösung des Atomdetektors beträgt ≈ 50 µm. Wir präsentieren auch
die Ergebnisse zur Demonstration von nicht-zerfließenden Wellenpaketen,
wie sie von Efremov et al. [1] vorhergesagt wurden. Die experimentellen
Ergebnisse zeigen sehr gute Übereinstimmung mit den theoretischen
Vorhersagen. Wir konnten durch Einsetzen einer interferometrischen Methode
nicht nur den Absolutbetrag der Wellenfunktion messen, sondern
auch Information über die quantenmechanische Phase deduzieren. Im
Speziellen werden wir diese Methode zur Phasenrekonstruktion im Detail
diskutieren.
[1] M.A. Efremov et al., Laser Phys., 13, 995 (2003); JETP, 97, 522
(2003).
Q 36.6 Do 14:00 Schellingstr. 3
EPR-Paare von Atomen aus der Photodissoziation von Molekülen
— •Alexander I. Lvovsky und Björn Brezger — Fachbereich
Physik M559, Universität Konstanz
Einstein, Podolsky und Rosen erkannten 1935 die Paradoxa, die ein
” EPR-Zustand“ mit idealer Orts- und Impulsverschränkung zwischen
zwei Teilchen aufwirft. Wir schlagen ein experimentelles Schema vor, wie
eine gute Annäherung an diesen Zustand erstmals mit massiven Teilchen
realisiert werden kann. Hierzu sollen Alkalidimere zunächst in einem Molekülstrahl
transversal kohärent präpariert und dann in einem stimulierten
Ramanprozess photodissoziiert werden. Die Transversalbewegung der
daraus hervorgehenden Atompaare ist verschränkt, was durch koinzidente
Detektion eindeutig nachgewiesen werden kann. Dieses bisher nicht
experimentell erforschte System bietet einen neuen Zugang zur Physik
verschränkter Systeme und ergänzt aufgrund seiner grundlegend anderen
Eigenschaften und der deutlich stärkeren Verschränkung die bisher
mit Photonenpaaren gemachten Experimente.
Q 36.7 Do 14:00 Schellingstr. 3
Resonance fluorescence of cold trapped atoms — •Wolfgang
Merkel, Marc Bienert, and Giovanna Morigi — Abteilung für
Quantenphysik, Universität Ulm, D-89069 Ulm
We investigate theoretically the spectrum of resonance fluorescence of
a cold trapped atom in the final stage of the laser cooling. We focus
on the features due to the mechanical effects of light in the limit where
the size of the atomic wavepacket is much smaller than the laser wavelength.
In particular, we discuss how these spectral features depend on
the internal configuration of the atom. The results obtained within a full
quantum mechanical model are compared with the limit when the motion
is treated semi-classically.
Q 36.8 Do 14:00 Schellingstr. 3
Phase-dependent nonlinear optics with atoms in a diamond configuration
of levels — •Sarah Schröder 1 , Giovanna Morigi 1 ,
and Sonja Franke-Arnold 2 — 1 Abteilung für Quantenphysik, Universität
Ulm, Germany — 2 Department of Physics, University of Strathclyde,
Glasgow, United Kingdom
We analyse the propagation of light in a medium of atoms with a diamond
configuration of levels. This atomic configuration is characterised
by a closed cycle of radiation-induced transitions, hence its dynamics and
steady-state depend critically on the relative phase between the driving
lasers [1]. In fact the relative phase can give rise to peculiar interference
effects, making the medium either transparent or opaque. We present
an analytical and numerical study of the propagation dynamics of the
light amplitude and phase as a function of the initial laser parameters
for this kind of medium, and compare our results with the dynamics of
light propagation in a medium of double-Λ atoms [2].
[1] G. Morigi, S. Franke-Arnold and G.-L. Oppo,
Phys. Rev. A 66, 053409 (2002)
tical lattice. For complete transfer we apply a sequence of narrow–band
laser pulses in a Raman configuration. We develop an idealized analytical
model and also perform a numerical analysis which accounts for the
actual vibrational structure of the optical lattice.
Q 36.10 Do 14:00 Schellingstr. 3
Laser-based approach to measuring quantum arrival times —
•Dirk Seidel and Gerhard C. Hegerfeldt — Tammannstrasse 1,
37077 Göttingen, Germany
We investigate a new operational approach to measuring the quantum
arrival-time distribution of a spread-out particle in a spatial region. The
model bases on illuminating the region with a laser and detecting the first
fluorescence photon produced by the excitation of the atom and subsequent
decay. The resulting temporal distribution is explicitly calculated
for the one-dimensional case. We show that by means of a deconvolution
one obtains the well known quantum mechanical probability flux
[1], whereas by a normalization of the corresponding temporal operator
function the axiomatic arrival-time distribution of Kijowski is recovered
[2].
[1] J.A. Damborenea, I.L. Egusquiza, G.C. Hegerfeldt, J.G. Muga, Phys.
Rev. A 66, 052104 (2002)
[2] G.C. Hegerfeldt, D. Seidel, J.G. Muga, Phys. Rev. A 68, 022111 (2003)
Q 36.11 Do 14:00 Schellingstr. 3
Wigner functions of s-waves. — •Alexander Wolf 1 , Jens
Peder Dahl 2 , Sandor Varro 3 , and Wolfgang Peter Schleich 1
— 1 Abteilung für Quantenphysik, Universität Ulm, D-89069 Ulm,
Germany — 2 Chemical Physics, Department of Chemistry,Technical
University of Denmark, DTU 207, DK-2800 Kgs. Lyngby, Denmark
— 3 Research Institute for Solid State Physics and Optics, H-1525
Budapest, PO Box 49, Hungary
We derive explicit expressions for the Wigner function of wave functions
in D dimensions corresponding to vanishing angular momentum,
that is of a s-wave. The Wigner function of such states depends on three
variables, the absolut value of the D-dimensional position and momentum
vectors and the angle between them. We illustrate these expression
by calculationg the Wigner function for a D-dimensional Gaussian, a
shell wave function and the energy eigenfunction of a free partical.
Q 36.12 Do 14:00 Schellingstr. 3
Microresonators in tapered fibers — •Florian Warken, Yann
Louyer, Dieter Meschede, and Arno Rauschenbeutel — Institut
für Angewandte Physik, Wegelerstr. 8, 53115 Bonn
We aim to realize high Q microresonators in structured tapered optical
fibers. The resonators have a highly prolate shape. They sustain whispering
gallery modes which exhibit, in contrast to the equatorial modes
commonly used in silica microsphere resonators, two spatially well separated
caustics with a resonantly enhanced field strength. Different modes
can be selectively excited by coupling light in and out of the resonator
at the respective caustic. This will be accomplished by means of auxiliary
tapered optical fiber couplers. Moreover, the free spectral range of
our so-called “pendulum modes” is significantly smaller than for equatorial
whispering gallery modes. Therefore, a tuning of the pendulum
modes over one free spectral range can easily be achieved, e. g. by strain
tuning. The advantageous mode geometry of the resonators, in combination
with their tunability, opens interesting perspectives for confining
and controlling light. In particular, in the framework of cavity quantum
electrodynamics, a deterministic coupling of laser-trapped atoms to the
pendulum mode is conceivable.
[2] E. A. Korsunsky and D. V. Kosachiov,
Phys. Rev. A 60, 4996 (1999)
Q 36.9 Do 14:00 Schellingstr. 3
Transport of Atoms in Optical Lattices — •Wolfgang Merkel1 ,
Holger Mack1 , Matthias Freyberger1 , Victor V. Kozlov1 ,
Bruce W. Shore2 , and Wolfgang P. Schleich1 — 1Abteilung für
Quantenphysik, Universität Ulm, D-89069 Ulm — 2 Q 36.13 Do 14:00 Schellingstr. 3
One- and N-atom lasers — •M. Hennrich, A. Kuhn, and G.
Rempe — Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-
Str. 1, 85748 Garching, Germany
The one-atom laser is the quantum-mechanical limit of a classical laser.
It is very appealing to examine the transition between these two regimes.
Here we describe a simple death-birth rate-equation model [1] of an atomcavity
system with fixed atom number N. The simplicity of this model
allows us to examine the transition from the microscopic one-atom to the
618 Escondido Circle, mesoscopic many-atom system.
Livermore CA 94550
Once placed in an optical cavity, the atoms can interact via the com-
We investigate the laser–induced transport of a single atom from one
mon mode. The interaction is negligible as long as the photons emitted
potential well to the neighbor potential well in a far off–resonance op-
into the cavity decay faster than they are reabsorbed by another atom.
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