D. Jaksch

University of Oxford, Oxford, England, United Kingdom

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Publications (24)80.56 Total impact

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    D. Jaksch, P. Zoller
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    ABSTRACT: We review recent theoretical advances in cold atom physics concentrating on strongly correlated cold atoms in optical lattices. We discuss recently developed quantum optical tools for manipulating atoms and show how they can be used to realize a wide range of many body Hamiltonians. Then, we describe connections and differences to condensed matter physics and present applications in the fields of quantum computing and quantum simulations. Finally, we explain how defects and atomic quantum dots can be introduced in a controlled way in optical lattice systems.
    Annals of Physics 01/2005; · 3.32 Impact Factor
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    D. Jaksch
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    ABSTRACT: We review novel methods to investigate, control and manipulate neutral atoms in optical lattices. These setups allow unprecedented quantum control over large numbers of atoms and thus are very promising for applications in quantum information processing. After introducing optical lattices we discuss the superfluid (SF) and Mott insulating (MI) states of neutral atoms trapped in such lattices and investigate the SF-MI transition as recently observed experimentally. In the second part of the paper we give an overview of proposals for quantum information processing and show different ways to entangle the trapped atoms, in particular the usage of cold collisions and Rydberg atoms. Finally, we also briefly discuss the implementation of quantum simulators, entanglement enhanced atom interferometers, and ideas for robust quantum memory in optical lattices. Comment: 29 pages, review article, accepted for publication in Contemporary Physics
    Contemporary Physics 07/2004; · 2.61 Impact Factor
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    ABSTRACT: We review theoretical proposals for implementation of quantum computing and quantum communication with quantum optical methods.
    Annales Henri Poincare 11/2003; 4:759-781. · 1.53 Impact Factor
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    ABSTRACT: We numerically study the behavior of collapsing and exploding condensates using the parameters of the experiments by E.A. Donley et al. [Nature, 412, 295, (2001)]. Our studies are based on a full three-dimensional numerical solution of the Gross-Pitaevskii equation (GPE) including three body loss. We determine the three body loss rate from the number of remnant condensate atoms and collapse times and obtain only one possible value which fits with the experimental results. We then study the formation of jet atoms by interrupting the collapse and find very good agreement with the experiment. Furthermore we investigate the sensitivity of the jets to the initial conditions. According to our analysis the dynamics of the burst atoms is not described by the GPE with three body loss incorporated. Comment: 9 pages, 10 figures
    Journal of Physics B Atomic Molecular and Optical Physics 07/2003; · 2.03 Impact Factor
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    D. Jaksch, P. Zoller
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    ABSTRACT: We investigate the dynamics of neutral atoms in a 2D optical lattice which traps two distinct internal states of the atoms in different columns. Two Raman lasers are used to coherently transfer atoms from one internal state to the other, thereby causing hopping between the different columns. By adjusting the laser parameters appropriately we can induce a non vanishing phase of particles moving along a closed path on the lattice. This phase is proportional to the enclosed area and we thus simulate a magnetic flux through the lattice. This setup is described by a Hamiltonian identical to the one for electrons on a lattice subject to a magnetic field and thus allows us to study this equivalent situation under very well defined controllable conditions. We consider the limiting case of huge magnetic fields -- which is not experimentally accessible for electrons in metals -- where a fractal band structure, the Hofstadter butterfly, characterizes the system. Comment: 6 pages, RevTeX
    New Journal of Physics 04/2003; · 4.06 Impact Factor
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    ABSTRACT: We propose the creation of a molecular Bose-Einstein condensate by loading an atomic condensate into an optical lattice and driving it into a Mott insulator with exactly two atoms per site. Molecules in a Mott insulator state are then created under well defined conditions by photoassociation with essentially unit efficiency. Finally, the Mott insulator is melted and a superfluid state of the molecules is created. We study the dynamics of this process and photoassociation of tightly trapped atoms.
    Physical Review Letters 08/2002; 89(4):040402. · 7.94 Impact Factor
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    ABSTRACT: We investigate schemes to dynamically create many particle entangled states of a two component Bose-Einstein condensate in a very short time proportional to 1/N where $N$ is the number of condensate particles. For small $N$ we compare exact numerical calculations with analytical semiclassical estimates and find very good agreement for $N \geq 50$. We also estimate the effect of decoherence on our scheme, study possible scenarios for measuring the entangled states, and investigate experimental imperfections. Comment: 12 pages, 8 figures
    Physical Review A 05/2002; · 3.04 Impact Factor
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    ABSTRACT: We review and compare several schemes for inducing precisely controlled quantum phases in quantum optical systems, We focus in particular on conditional dynamical phases, i.e. phases obtained via state- and time-dependent interactions between trapped two-level atoms and ions, We describe different possibilities for the kind of interaction to be exploited, including cold controlled collisions, electrostatic forces, and dipole-dipole interactions.
    Journal of Optics B Quantum and Semiclassical Optics 01/2002; · 1.81 Impact Factor
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    D. Jaksch, J. I. Cirac, P. Zoller
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    ABSTRACT: We propose a mechanism to change the interaction strengths of a two component condensate. It is shown that the application of pi/2 pulses allows to alter the effective interspecies interaction strength as well as the effective interaction strength between particles of the same kind. This mechanism provides a simple method to transform spatially stable condensates into unstable once and vice versa. It also provides a means to store a squeezed spin state by turning off the interaction for the internal states and thus allows to gain control over many body entangled states. Comment: 7 pages 5 figures, symbols changed, minor changes, to appear in Phys. Rev. A
    Physical Review A 10/2001; · 3.04 Impact Factor
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    ABSTRACT: We describe a technique for manipulating quantum information stored in collective states of mesoscopic ensembles. Quantum processing is accomplished by optical excitation into states with strong dipole-dipole interactions. The resulting "dipole blockade" can be used to inhibit transitions into all but singly excited collective states. This can be employed for a controlled generation of collective atomic spin states as well as nonclassical photonic states and for scalable quantum logic gates. An example involving a cold Rydberg gas is analyzed.
    Physical Review Letters 08/2001; 87(3):037901. · 7.94 Impact Factor
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    ABSTRACT: The relative phase of two initially independent Bose-Einstein condensates can be laser cooled to unite the two condensates by putting them into a ring cavity and coupling them with an internal Josephson junction. First, we show that this phase cooling process already appears within a semiclassical model. We calculate the stationary states, find regions of bistable behavior, and suggest a Ramsey-type experiment to measure the buildup of phase coherence between the condensates. We also study quantum effects and imperfections of the system.
    Physical Review Letters 06/2001; 86(21):4733-6. · 7.94 Impact Factor
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    ABSTRACT: We review recent proposals for performing entanglement manipulation via cold collisions between neutral atoms. State-dependent, time-varying trapping potentials allow one to control the interaction between atoms, so that conditional phase shifts realizing a universal quantum gate can be obtained with high fidelity. We discuss possible physical implementations with existing experimental techniques, for example optical lattices and magnetic micro-traps.
    Journal of Modern Optics 12/2000; · 1.16 Impact Factor
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    ABSTRACT: We propose several schemes for implementing a fast two-qubit quantum gate for neutral atoms with the gate operation time much faster than the time scales associated with the external motion of the atoms in the trapping potential. In our example, the large interaction energy required to perform fast gate operations is provided by the dipole-dipole interaction of atoms excited to low-lying Rydberg states in constant electric fields. A detailed analysis of imperfections of the gate operation is given.
    Physical Review Letters 10/2000; 85(10):2208-11. · 7.94 Impact Factor
  • Dieter Jaksch, Tommaso Calarco, Peter Zoller
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    ABSTRACT: Die Quantenmechanik eröffnet faszinierende Perspektiven für die Kommunikation und die Informationsverarbeitung. Um universell programmierbare Quantenrechner realisieren zu können bedarf es der Implementierung von Konzepten zur Quanteninformationsverarbeitung die sich auf eine große Anzahl von Qubits anwenden lassen.
    Physik in unserer Zeit 01/2000; 31(6):260-266.
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    ABSTRACT: We present quantum optical systems that implement quantum computing tasks concentrating on two-qubit gates. We investigate two novel schemes, based on (i) dipole moments of (neutral) Rydberg atoms and, (ii) on conditional Coulomb interactions between ions in arrays of micro-traps.
    01/2000;
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    ABSTRACT: We review recent proposals for performing entanglement manipulation via controlled interactions between trapped atoms. State-dependent, time-varying microscopic potentials allow one to obtain with high fidelity a conditional phase shift realizing a universal quantum gate. We discuss possible physical implementations with existing experimental techniques, for example optical lattices and magnetic micro-traps.
    Fortschritte Der Physik-progress of Physics - FORTSCHR PHYS. 01/2000; 48:175 - 185.
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    ABSTRACT: We consider the case of a cubic nonlinear Schr\"{o}dinger equation with an additional chaotic potential, in the sense that such a potential produces chaotic dynamics in classical mechanics. We derive and describe an appropriate semiclassical limit to such a nonlinear Schr\"{o}dinger equation, using a semiclassical interpretation of the Wigner function, and relate this to the hydrodynamic limit of the Gross-Pitaevskii equation used in the context of Bose-Einstein condensation. We investigate a specific example of a Gross-Pitaevskii equation with such a chaotic potential: the one-dimensional delta-kicked harmonic oscillator, and its semiclassical limit. We explore the feasibility of experimental realization of such a system in a Bose-Einstein condensate experiment, giving a concrete proposal of how to implement such a configuration, and considering the problem of condensate depletion. Comment: 20 pages text, 20 gzipped ps and eps figures
    Physical Review A 12/1999; · 3.04 Impact Factor
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    ABSTRACT: Controlled cold collisions of atoms in optical lattices allow implementations of highly parallel entanglement operations and quantum gates. Applications include quantum computing with efficient quantum error correction. Existing experimental techniques for cooling and trapping of atoms in optical lattices, combined with the physics of ultracold collisions (BEC) offer a new perspective for quantum information experiments. We propose the use of cold controlled collisions of atoms, trapped in the ground state of the lattice wells, as a mechanism to introduce dynamic phase shifts depending on the state of the atoms. In conventional lattices with random occupation of the lattice sites, this mechanism can be used, for example, for spectroscopic studies of entangled Bell and GHZ states. In lattices with ordered filling structures, which have been discussed theoretically (Mott insulator phase), highly parallel entanglement operations could be implemented, corresponding to a novel class of quantum gates. We show that these (multi-qubit) quantum gates can be employed for efficient quantum error correction and discuss how the parallelism in an optical lattice could be used for quantum computation in general
    Quantum Electronics and Laser Science Conference, 1999. QELS '99. Technical Digest. Summaries of Papers Presented at the; 06/1999
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    ABSTRACT: We develop a method to entangle neutral atoms using cold controlled collisions. We analyze this method in two particular set-ups: optical lattices and magnetic micro-traps. Both offer the possibility of performing certain multi-particle operations in parallel. Using this fact, we show how to implement efficient quantum error correction and schemes for fault-tolerant computing.
    Journal of Modern Optics 05/1999; · 1.16 Impact Factor
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    ABSTRACT: We theoretically study specific schemes for performing a fundamental two-qubit quantum gate via controlled atomic collisions by switching microscopic potentials. In particular we calculate the fidelity of a gate operation for a configuration where a potential barrier between two atoms is instantaneously removed and restored after a certain time. Possible implementations could be based on microtraps created by magnetic and electric fields, or potentials induced by laser light. Comment: 10 pages, 3 figures
    Physical Review A 01/1999; 61(2):022304. · 3.04 Impact Factor

Publication Stats

1k Citations
58 Downloads
889 Views
80.56 Total Impact Points

Institutions

  • 2003–2005
    • University of Oxford
      • Department of Physics
      Oxford, England, United Kingdom
  • 1997–2005
    • University of Innsbruck
      • Department of Theoretical Physics
      Innsbruck, Tyrol, Austria
  • 2001
    • Harvard-Smithsonian Center for Astrophysics
      • Institute for Theoretical Atomic, Molecular and Optical Physics
      Cambridge, Massachusetts, United States
  • 1998
    • Antioch University, Santa Barbara
      Santa Barbara, California, United States