Jörg Schmiedmayer - Profile on Academia.edu (original) (raw)

Papers by Jörg Schmiedmayer

Tailored periodic potentials in atom optics

ABSTRACT

Atom Waves In Crystals Made Of Light

Quantum Electronics and Laser Science Conference, May 18, 1997

Atoms interacting with standing light waves are a model system for the propagation of waves in st... more Atoms interacting with standing light waves are a model system for the propagation of waves in static and time varying periodic media. We present here experiments studying the coherent motion of atomic deBroglie waves in periodic potentials made from on and off resonant light. We observe anomalous transmission of atoms through resonant standing light waves and experimentally confirm that atoms

Atom Optics with Microtraps and Atom Chips;: Assembling Tools for Quantum Information Processing

Laser Spectroscopy, 2004

ABSTRACT Magnetic microtraps and atom chips have proven to be small-scale, reliable and flexible ... more ABSTRACT Magnetic microtraps and atom chips have proven to be small-scale, reliable and flexible tools to prepare ultra-cold and degenerate atom clouds as sources for various atom-optical experiments. We present a short overview of several possibilities of the devices, including the first results of using electrostatic interaction to realise traps.

$Research paper thumbnail of Matter-wave diffraction at light holograms$

Matter-wave diffraction at light holograms

EQEC 96 1996 European Quantum Electronic Conference EQEC-96, 1996

Atom waves in crystals made of light

SPIE Proceedings, 1997

Ultracold atoms on atom chips: Manipulation at the μm distance scale

Miniaturized potentials near the surface of atom chips can be used as flexible and versatile tool... more Miniaturized potentials near the surface of atom chips can be used as flexible and versatile tools for the manipulation of ultracold atoms on a microscale. The full scope of possibilities is only accessible if atom-surface distances can be reduced to microns. We discuss experiments in this regime and potential obstacles and solutions. We show that appropriate fabrication techniques lead to a reduction of disorder potentials so that one-dimensional condensates can be prepared. We demonstrate how electrostatic potentials can be used to modify magnetic trapping potentials and how they can be used to study condensate formation in situations of different dimensionality.

Coherent matter wave optics on an atom chip

ABSTRACT Coherent manipulation of matter waves in microscopic trapping potentials facilitates bot... more ABSTRACT Coherent manipulation of matter waves in microscopic trapping potentials facilitates both fundamental and technological applications. Here we focus on experiments with a microscopic integrated interferometer that demonstrate coherent operation on an atom chip.

Science, 2012

Understanding relaxation processes is an important unsolved problem in many areas of physics. A k... more Understanding relaxation processes is an important unsolved problem in many areas of physics. A key challenge in studying such non-equilibrium dynamics is the scarcity of experimental tools for characterizing their complex transient states. We employ measurements of full quantum mechanical probability distributions of matter-wave interference to study the relaxation dynamics of a coherently split one-dimensional Bose gas and obtain unprecedented information about the dynamical states of the system. Following an initial rapid evolution, the full distributions reveal the approach towards a thermal-like steady state characterized by an effective temperature that is independent from the initial equilibrium temperature of the system before the splitting process. We conjecture that this state can be described through a generalized Gibbs ensemble and associate it with pre-thermalization.

Interferometry with atoms and molecules: A tutorial

Atom Optics, 1997

Interferometry with atoms and molecules: a tutorial. [Proceedings of SPIE 2995, 22 (1997)]. David... more Interferometry with atoms and molecules: a tutorial. [Proceedings of SPIE 2995, 22 (1997)]. David E. Pritchard, Michael S. Chapman, Christopher R. Ekstrom, Troy D. Hammond, David A. Kokorowski, Alan Lenef, Richard A. Rubenstein, Joerg Schmiedmayer, Edward T. Smith. ...

AIP Conference Proceedings, 2014

Non-equilibrium dynamics of isolated quantum many-body systems play an important role in many are... more Non-equilibrium dynamics of isolated quantum many-body systems play an important role in many areas of physics. However, a general answer to the question of how these systems relax is still lacking. We experimentally study the dynamics of ultracold one-dimensional (1D) Bose gases. This reveals the existence of a quasi-steady prethermalized state which differs significantly from the thermal equilibrium of the system. Our results demonstrate that the dynamics of nonequilibrium quantum many-body systems is a far richer process than has been assumed in the past.

Quantum Information Processing, 2011

We investigate quantum information processing, transfer and storage in hybrid systems comprised o... more We investigate quantum information processing, transfer and storage in hybrid systems comprised of diverse blocks integrated on chips. Strong coupling between superconducting (SC) qubits and ensembles of ultracold atoms or NV-center spins is mediated by a microwave transmission-line resonator that interacts near-resonantly with the atoms or spins. Such hybrid devices allow us to benefit from the advantages of each block and compensate for their disadvantages. Specifically, the SC qubits can rapidly implement quantum logic gates, but are "noisy" (prone to decoherence), while collective states of the atomic or spin ensemble are "quiet"(protected from decoherence) and thus can be employed for storage of quantum information. To improve the overall performance (fidelity) of such devices we discuss dynamical control to optimize quantum state-transfer from a "noisy" qubit to the "quiet" storage ensemble. We propose to maximize the fidelity of transfer and storage in a spectrally inhomogeneous spin ensemble, by pre-selecting the optimal spectral portion of the ensemble. Significant improvements of the overall fidelity of hybrid devices are expected under realistic conditions. Experimental progress towards the realization of these schemes is discussed.

A Double Well Interferometer on an Atom Chip

Quantum Information Processing, 2006

Radio-Frequency coupling between magnetically trapped atomic states allows to create versatile ad... more Radio-Frequency coupling between magnetically trapped atomic states allows to create versatile adiabatic dressed state potentials for neutral atom manipulation. Most notably, a single magnetic trap can be split into a double well by controlling amplitude and frequency of an oscillating magnetic field. We use this to build an integrated matter wave interferometer on an atom chip. Transverse splitting of quasi

Physical Review Letters, 2003

We report on experiments with cold thermal 7 Li atoms confined in combined magnetic and electric ... more We report on experiments with cold thermal 7 Li atoms confined in combined magnetic and electric potentials. A novel type of three-dimensional trap was formed by modulating a magnetic guide using electrostatic fields. We observed atoms trapped in a string of up to six individual such traps, a controlled transport of an atomic cloud over a distance of 400µm, and a dynamic splitting of a single trap into a double well potential. Applications for quantum information processing are discussed.

Physical Review A, 2000

Temporal light modulation methods which are of great practical importance in optical technology, ... more Temporal light modulation methods which are of great practical importance in optical technology, are emulated with matter waves. This includes generation and tailoring of matter-wave sidebands, using amplitude and phase modulation of an atomic beam. In the experiments atoms are Bragg diffracted at standing light fields, which are periodically modulated in intensity or frequency. This gives rise to a generalized Bragg situation under which the atomic matter waves are both diffracted and coherently shifted in their de Broglie frequency. In particular, we demonstrate creation of complex and non-Hermitian matter-wave modulations. One interesting case is a potential with a time-dependent complex helicity ͓Vϰexp(it)͔, which produces a purely lopsided energy transfer between the atoms and the photons, and thus violates the usual symmetry between absorption and stimulated emission of energy quanta. Possible applications range from atom cooling over advanced atomic interferometers to a new type of mass spectrometer.

Physical Review A, 2005

We present an omnidirectional matter wave guide on an atom chip. The rotational symmetry of the g... more We present an omnidirectional matter wave guide on an atom chip. The rotational symmetry of the guide is maintained by a combination of two current carrying wires and a bias field pointing perpendicular to the chip surface. We demonstrate guiding of thermal atoms around more than two complete turns along a spiral shaped 25mm long curved path (curve radii down to 200µm) at various atom-surface distances (35-450µm). An extension of the scheme for the guiding of Bose-Einstein condensates is outlined.

Physical Review A, 2012

We propose a method to maximize the fidelity of quantum memory implemented by a spectrally inhomo... more We propose a method to maximize the fidelity of quantum memory implemented by a spectrally inhomogeneous spin ensemble. The method is based on preselecting the optimal spectral portion of the ensemble by judiciously designed pulses. This leads to significant improvement of the transfer and storage of quantum information encoded in the microwave or optical field.

Physical Review A, 2009

We examine the possibility of coherent, reversible information transfer between solid-state super... more We examine the possibility of coherent, reversible information transfer between solid-state superconducting qubits and ensembles of ultra-cold atoms. Strong coupling between these systems is mediated by a microwave transmission line resonator that interacts near-resonantly with the atoms via their optically excited Rydberg states. The solid-state qubits can then be used to implement rapid quantum logic gates, while collective metastable states of the atoms can be employed for long-term storage and optical read-out of quantum information.

Optics Letters, 2004

We present an omnidirectional matter waveguide on an atom chip. The guide is based on a combinati... more We present an omnidirectional matter waveguide on an atom chip. The guide is based on a combination of two current-carrying wires and a bias field pointing perpendicular to the chip surface. Thermal atoms are guided for more than two complete turns along a 25-mm-long spiral path (with curve radii as short as 200 mm) at various atom-surface distances (35 450 mm). An extension of the scheme for the guiding of Bose -Einstein condensates is outlined.

New Journal of Physics, 2013

We detail the experimental observation of the non-equilibrium many-body phenomenon prethermalizat... more We detail the experimental observation of the non-equilibrium many-body phenomenon prethermalization. We study the dynamics of a rapidly and coherently split one-dimensional Bose gas. An analysis based on the use of full quantum mechanical probability distributions of matter wave interference contrast reveals that the system evolves towards a quasi-steady state. This state, which can be characterized by an effective temperature, is not the final thermal equilibrium state. We compare the evolution of the system to an integrable Tomonaga-Luttinger liquid model, and show that the system dephases to a prethermalized state rather than undergoing thermalization towards a final thermal equilibrium state.