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Quantum technologies

Dieter Meschede's research group
Home Group members Martin Müller
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Dipl.-Phys. Martin Müller
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PhD student
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Publications(up to 2005)

  • M. Mützel, M. Müller, D. Haubrich, U. Rasbach, D. Meschede, C. O’Dwyer, G. Gay, B. V. d. Lesegno, J. Weiner, K. Ludolph, G. Georgiev and E. Oesterschulze
    The atom pencil: serial writing in the sub-micrometre domain, Appl. Phys. B 80, 941 (2005)BibTeXPDF
    The atom pencil we describe here is a versatile tool that writes arbitrary structures by atomic deposition in a serial lithographic process. This device consists of a transversely laser-cooled and collimated cesium atomic beam that passes through a 4-pole atom-flux concentrator and impinges on to micron- and sub-micron-sized apertures. The aperture translates above a fixed substrate and enables the writing of sharp features with sizes down to 280 nm. We have investigated the writing and clogging properties of an atom pencil tip fabricated from silicon oxide pyramids perforated at the tip apex with a sub-micron aperture.
  • I. Dotsenko, W. Alt, S. Kuhr, D. Schrader, M. Müller, Y. Miroshnychenko, V. Gomer, A. Rauschenbeutel and D. Meschede
    Application of electro-optically generated light fields for Raman spectroscopy of trapped Cesium atoms, Appl. Phys. B 78, 711-717 (2004)BibTeXPDF
    We present an apparatus for generating a multi-frequency laser field to coherently couple the F=3 and F=4 ground state of trapped cesium atoms through Raman transitions. We use a single frequency diode laser and generate sidebands by means of a 9.2 GHz electro-optic modulator. With an interferometer, we separated the sidebands and carrier, sending them to the trapped atoms in opposite directions. The Rabi oscillation of the populations of F=3 and F=4 is monitored. We find that due to destructive quantum interference of two simultaneous Raman transitions the expected Rabi frequency is reduced by a factor that is in quantitative agreement with theoretical expectations. It is demonstrated how this interference can be suppressed experimentally. Besides, we demonstrate the application of the setup for Raman spectroscopy of Zeeman sublevels and of the vibrational states of a small number of trapped atoms.
  • W. Alt, D. Schrader, S. Kuhr, M. Müller, V. Gomer and D. Meschede
    Single atoms in a standing-wave dipole trap, Phys. Rev. A 67, 033403 (2003)arXivBibTeXPDF
    We trap a single cesium atom in a standing-wave optical dipole trap. Special experimental procedures, designed to work with single atoms, are used to measure the oscillation frequency and the atomic energy distribution in the dipole trap. These methods rely on unambiguously detecting presence or loss of the atom using its resonance fluorescence in the magneto-optical trap.
  • S. Kuhr, W. Alt, D. Schrader, M. Müller, V. Gomer and D. Meschede
    Deterministic Delivery of a Single Atom, Science 293, 278 (2001)BibTeXPDF
    We report the realization of a deterministic source of single atoms. A standing-wave dipole trap is loaded with one or any desired number of cold cesium atoms from a magneto-optical trap. By controlling the motion of the standing wave, we adiabatically transport the atom with submicrometer precision over macroscopic distances on the order of a centimeter. The displaced atom is observed directly in the dipole trap by fluorescence detection. The trapping field can also be accelerated to eject a single atom into free flight with well-defined velocities.
  • M. Müller
    Ramankühlung einzelner Atome, (2001), Diplom thesisBibTeXPDF
    Ausgehend von den theoretischen Überlegungen wurde ein Schema zur Raman-Seitenbandkühlung eines in der optischen Dipolfalle gespeicherten Atoms vorgestellt. Hierbei wurden alle für unser Experiment wichtigen Parameter berechnet und zusätzlich die erforderlichen Bedingungen für das benötigte Lasersystem festgelegt. Dieses Lasersystem wurde aufgebaut und getestet. Mit Hilfe eines EOMs wurden die beiden Ramanlaser mit der zur Seitenbandkühlung notwendigen stabilen Differenzfrequenz erzeugt. Um effektives Kühlen zu ermöglichen, wurden die beiden Frequenzen anschließend durch ein HDW-Interferometer räumlich voneinander getrennt. Somit werden auch die experimentellen Voraussetzungen für die Raman-Seitenbandkühlung erfüllt. Man steht daher kurz vor dem Ziel, ein einzelnes Atom in den niedrigsten gebundenen Zustand im Potenzial einer optischen Dipolfalle zu überführen.
  • D. Schrader, S. Kuhr, W. Alt, M. Müller, V. Gomer and D. Meschede
    An optical conveyor belt for single neutral atoms, Appl. Phys. B 73, 819 (2001)arXivBibTeXPDF
    Using optical dipole forces we have realized controlled transport of a single or any desired small number of neutral atoms over a distance of a centimeter with sub-micrometer precision. A standing wave dipole trap is loaded with a prescribed number of cesium atoms from a magneto-optical trap. Mutual detuning of the counter-propagating laser beams moves the interference pattern, allowing us to accelerate and stop the atoms at preselected points along the standing wave. The transportation efficiency is close to 100%. This optical "single-atom conveyor belt" represents a versatile tool for future experiments requiring deterministic delivery of a prescribed number of atoms on demand.
  • W. G. Kaenders, F. Lison, I. Müller, A. Richter, R. Wynands and D. Meschede
    Refractive components for magnetic atom optics, Phys. Rev. A 54, 5067 (1996)BibTeXPDF

    With strong rare-earth permanent magnets we have built highly refractive atom-optical components for laser-cooled atoms. We have studied the influence of axially symmetric multipole components on a cesium atomic beam. In analogy to traditional optics the action of a quadrupole ring parallels a conical prism, or axicon. Hexapole lenses were applied for focusing with a more than 1000-fold increase in atomic flux density at the focal spot and for imaging with the atomic beam. Two hexapole lenses were combined to form a telescope, which was operated off axis in order to separate fast thermal and slowed atoms. The experiments can approximately be described in terms of geometrical optics.