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Search Publications by: Dietrich Leibfried (Fed)

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Displaying 101 - 125 of 136

Surface-Electrode Architecture for Ion-Trap Quantum Information Processing

September 1, 2005
Author(s)
J Chiaverini, Brad R. Blakestad, Joseph W. Britton, John D. Jost, C. Langer, Dietrich G. Leibfried, R Ozeri, David J. Wineland
We investigate a surface-mounted electrode geometry for miniature linear radio frequency Paul ion traps. The electrodes reside in a single plane on a substrate, and the pseudopotential minimum of the trap is located above the substrate at a distance on

Long-Lived Qubit Memory Using Atomic Ions

August 5, 2005
Author(s)
C. Langer, R Ozeri, John D. Jost, J Chiaverini, B. L. DeMarco, A. Ben-Kish, Brad R. Blakestad, Joseph W. Britton, David Hume, Wayne M. Itano, Dietrich G. Leibfried, Rainer Reichle, Till P. Rosenband, Tobias Schaetz, Piet Schmidt, David J. Wineland
We demonstrate experimentally a robust quantum memory using a magnetic-field-independent hyperfine transition in 9Be + atomic ioin qubits at a magnetic field B=0.01194 T. We observe the single physical qubit memory coherence time to be greater than 10

Hyperfine Coherence in the Presence of Spontaneous Photon Scattering

July 15, 2005
Author(s)
R Ozeri, C. Langer, John D. Jost, B. L. DeMarco, A. Ben-Kish, Brad R. Blakestad, Joseph W. Britton, J Chiaverini, Wayne M. Itano, David Hume, Dietrich G. Leibfried, Till P. Rosenband, Piet Schmidt, David J. Wineland
The coherence of hyperfine-state superpositions of a trapped 9Be + ion is experimentally studied in the presence of off-resonant light. It is shown that Rayleigh elastic scattering of photons that does not change state populations also does not affect

Quantum Control, Quantum Information Processing, and Quantum-Limited Metrology With Trapped Ions

June 19, 2005
Author(s)
David J. Wineland, Dietrich G. Leibfried, Murray D. Barrett, A. Ben-Kish, James C. Bergquist, Brad R. Blakestad, John J. Bollinger, Joseph W. Britton, J Chiaverini, B. L. DeMarco, David Hume, Wayne M. Itano, M J. Jensen, John D. Jost, Emanuel H. Knill, Jeroen Koelemeij, C. Langer, Windell Oskay, R Ozeri, Rainer Reichle, Till P. Rosenband, Tobias Schaetz, Piet Schmidt, Signe Seidelin
We briefly discuss recent experiments on quantum informaiton processing using trapped ions at NIST. A central theme of this work has been to increase our capabilities in terms of quantum computing protocols, but we have also been interested in applying the

Implementation of the semiclassical quantum Fourier transform in a scalable system

May 13, 2005
Author(s)
J Chiaverini, Joseph W. Britton, Dietrich G. Leibfried, Emanuel H. Knill, Murray D. Barrett, Brad R. Blakestad, Wayne M. Itano, John D. Jost, C. Langer, R Ozeri, Tobias Schaetz, David J. Wineland
One of the most interesting future applications of quantum computers is Shor's factoring algorithm, which provides an exponential speedup compared to known classical algorithms. The crucial final step in Shor's algorithm is the quantum Fourier transform

Enhanced Quantum State Detection Efficiency Through Quantum Information Processing

January 1, 2005
Author(s)
T Schaetz, Murray D. Barrett, Dietrich G. Leibfried, Joseph W. Britton, J Chiaverini, Wayne M. Itano, John D. Jost, E Knill, Christopher Langer, David J. Wineland
We investigate theoretically and experimentally how quantum state-detection efficiency is improved by the use of quantum information processing (QIP). Experimentally, we encode the state of one 9Be ion qubit with one additional ancilla qubit. By measuring

Realization of quantum error correction

December 2, 2004
Author(s)
J Chiaverini, Dietrich G. Leibfried, Tobias Schaetz, Murray D. Barrett, Brad R. Blakestad, Joseph W. Britton, Wayne M. Itano, John D. Jost, Emanuel H. Knill, C. Langer, R Ozeri, David J. Wineland
Scalable quantum computation and communication require error control to protect quantum information against unavoidable noise. Quantum error correction protects quantum information stored in two-level quantum systems (qubits) by rectifying errors with

Quantum information processing with trapped ions

July 25, 2004
Author(s)
Murray D. Barrett, Tobias Schaetz, J Chiaverini, Dietrich Leibfried, Joseph W. Britton, Wayne M. Itano, John D. Jost, Emanuel Knill, C. Langer, R Ozeri, David J. Wineland
We report experiments on the creation and manipulation ofmulti-particle entangled states of trapped atomic ions. The experiments reported here, quantum dense coding and quantum teleportation, constitute a significant step toward performing large-scale

Quantum Dense Coding with Atomic Qubits

January 1, 2004
Author(s)
T Schaetz, Murray D. Barrett, Dietrich G. Leibfried, J Chiaverini, Joseph W. Britton, Wayne M. Itano, John D. Jost, Christopher Langer, David J. Wineland
We report the implementation of quantum dense coding on individual atomic qubits with the use of two trapped 9Be+ ions. The protocol is implemented with a complete Bell measurement that distinguishes the four operations used to encode two bits of classical

Toward Heisenberg-Limited Spectroscopy with Multiparticle Entangled States

January 1, 2004
Author(s)
Dietrich G. Leibfried, Murray D. Barrett, T Schaetz, Joseph W. Britton, J Chiaverini, Wayne M. Itano, John D. Jost, Christopher Langer, David J. Wineland
The precision in spectroscopy of any quantum system is fundamentally limited by the Heisenberg uncertainty relation for energy and time. For N systems, this limit requires that they be in a quantum-mechanically entangled state. We describe a scalable

Ion Optical Clocks and Quantum Information Processing

May 1, 2003
Author(s)
David J. Wineland, James C. Bergquist, Till P. Rosenband, Piet Schmidt, Wayne M. Itano, John J. Bollinger, Dietrich G. Leibfried, W Oskay
We summarize experiments at NIST that (1) use guantum gates to entabgle ions and thereby improve the measurement signal-to-noise ratio in spectroscopy and (2) implement sympathetic cooling and quantum state transfer techniques, which might be used to

Experimental Demonstration of a Technique to Generate Arbitrary Quantum Superposition States of a Harmonically Bound Spin-1/2 Particle

January 24, 2003
Author(s)
A Ben-kish, B M. Demarco, V Meyer, Mary A. Rowe, Joseph W. Britton, Wayne M. Itano, Branislav M. Jelenkovic, Christopher Langer, Dietrich Leibfried, Till P. Rosenband, David J. Wineland
Using a single, harmonically trapped 9Be+ ion, we experimentally demonstrate a technique for generation of arbitrary states of a two-level particle confined by a harmonic potential. Rather than engineering a single Hamiltonian that evolves the system to a

Building Blocks for a Scalable Quantum Information Processor Based On Trapped Ions

January 1, 2003
Author(s)
Dietrich G. Leibfried, Murray D. Barrett, A Ben-kish, Joseph W. Britton, J Chiaverini, B. L. DeMarco, Wayne M. Itano, Branislav M. Jelenkovic, John D. Jost, Christopher Langer, D Lucas, V Meyer, Till P. Rosenband, M A. Rowe, T Schaetz, David J. Wineland
We describe the underlying concept and experimental demonstration of the basic building blocks of a scalable quantum information processor architecture using trapped ion-qubits. The trap structure is divided into many subregions. In each several ion-qubits

Experimental demonstration of robust, high-fidelity geometric two ion-qubit phase gate

January 1, 2003
Author(s)
Dietrich G. Leibfried, B. L. DeMarco, V Meyer, D Lucas, Murray D. Barrett, Joseph W. Britton, Wayne M. Itano, Branislav M. Jelenkovic, Christopher Langer, Till P. Rosenband, David J. Wineland
Universal logic gates for two quantum bits (qubits) form an essential ingredient of quantum computation. Dynamical gates have been proposed in the context of trapped ions; however, geometric phase gates (which change only the phase of the physical qubits)

Quantum information processing and multiplexing with trapped ions

January 1, 2003
Author(s)
David J. Wineland, Dietrich G. Leibfried, B. L. DeMarco, V Meyer, M A. Rowe, A Ben kish, Murray D. Barrett, Joseph W. Britton, J Hughes, Wayne M. Itano, Branislav M. Jelenkovic, Christopher Langer, D Lucas, Till P. Rosenband
We report experiments on coherent quantum-state synthesis and control of trapped atomic ions. This work has the overall goal of performing large-scale quantum information processing; however, such techniques can also be applied to fundamental tests and

Quantum information processing with trapped ions,

January 1, 2003
Author(s)
David J. Wineland, Murray D. Barrett, Joseph W. Britton, J Chiaverini, B. L. DeMarco, Wayne M. Itano, Branislav M. Jelenkovic, Christopher Langer, Dietrich G. Leibfried, Till P. Rosenband, T Schaetz
Experiments directed towards the development of a quantum computer based on trapped atomic ions are described briefly. We discuss the implementation of single-qubit operations and gates between qubits. A geometric phase gate between two ion qubits is

Sympathetic cooling of 9 Be + and 24 Mg + for quantum logic

January 1, 2003
Author(s)
Murray D. Barrett, B. L. DeMarco, T Schaetz, Dietrich Leibfried, Joseph W. Britton, J Chiaverini, Wayne M. Itano, Branislav M. Jelenkovic, John D. Jost, Christopher Langer, Till P. Rosenband, David J. Wineland
We demonstrate the cooling of a two species ion crystal consisting of one 9Be+ and one 24Mg+ ion. Since the respective cooling transitions of these two species are separated by more than 30 nm, laser manipulation of one ion has negligible effect on the

Towards quantum information with trapped ions at NIST

January 1, 2003
Author(s)
Dietrich G. Leibfried, B. L. DeMarco, V Meyer, M A. Rowe, A Ben-kish, Murray D. Barrett, Joseph W. Britton, J Hughes, Wayne M. Itano, Branislav M. Jelenkovic, Christopher Langer, D Lucas, Till P. Rosenband, David J. Wineland
We report experiments on coherent quantum-state synthesis and the control of trapped atomic ions. This work has the overall goal of performing large-scale quantum information processing; however, such techniques can also be applied to fundamental tests and

Trapped Ions, Entanglement, and Quantum Computing

May 1, 1998
Author(s)
C J. Myatt, B E. King, D Kielpinski, Dietrich Leibfried, C S. Turchette, Chris S. Wood, Wayne M. Itano, C Monroe, David J. Wineland
A miniature, elliptical ring rf (Paul) ion trap has been used in recent experiments toward realizing a quantum computer in a trapped ion system. With the combination fo small spatial dimensions and high rf drive potentials, around 500 V amplitude, we have

Coherent Quantum State Manipulation of Trapped Atomic Ions

January 1, 1998
Author(s)
David J. Wineland, C Monroe, D M. Meekhof, B E. King, Dietrich G. Leibfried, Wayne M. Itano, James C. Bergquist, D J. Berkeland, John J. Bollinger, J D. Miller
A single, laser-cooled, trapped 9Be+ ion is used to investigate methods of coherent quantum-state synthesis. We create and characterize nonclassical states of motion including "Schrödinger- cat" states. A fundamental quantum logic gate is realized using

Experimental Issues in Coherent Quantum-State Manipulation of Trapped Atomic Ions,

January 1, 1998
Author(s)
David J. Wineland, C Monroe, Wayne M. Itano, Dietrich G. Leibfried, B E. King, D M. Meekhof
Methods for, and limitations to, the generation of entangled states of trapped atomic ions are examined. As much as possible, state manipulations are described in terms of quantum logic operations since the conditional dynamics implicit in quantum logic is