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Search Publications

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Displaying 826 - 850 of 871

Implementing a Multiplexed System of Detectors for Higher Photon Counting Rates

July 1, 2007
Author(s)
V Schettini, Sergey Polyakov, Ivo P. Degiovanni, Giorgio Brida, Stefania Castelletto, Alan L. Migdall
Photon counting applications are often limited by detector deadtime to operate at count rates of a few MHz, at best, and often at significantly lower levels. This limitation is becoming more critical as with the advance of photon counting applications such

Quantum key distribution over a 40-dB channel loss using superconducting single-photon detectors

June 1, 2007
Author(s)
Hiroki Takesue, Sae Woo Nam, Qiang Zhang, Robert Hadfield, Toshimori Honjo, Kiyoshi Tamaki, Yoshihisa Yamamoto
We report the first quantum key distribution (QKD) experiment to enable the creation of secure keys over 42 dB channel loss and 200 km of optical fibre. We used the differential phase shift QKD (DPS-QKD) protocol, implemented with a 10-GHz clock frequency

A Broadband High Spectral Brightness Fiber-Based Two-Photon Source

March 19, 2007
Author(s)
Jingyun Fan, Alan L. Migdall
After characterizing the Raman scattering in a fused silica polarization-maintaining microstructure optical fiber, we built a fiber-based two-photon light source of high spectral brightness, broad spectral range, and very low noise background at room

Achieving Higher Photon Counting Rates Using Multiplexed Detectors

August 13, 2006
Author(s)
Stefania Castelletto, Ivo P. Degiovanni, Alan L. Migdall, Sergey Polyakov, V Schettini
As the quantum information field advances, the need for improved single-photon devices is becoming more critical. Quantum information systems are often limited by detector deadtime to count rates of a few MHz, at best. We present a multiplexed detection

Efficient generation of correlated photon pairs in a microstructure fiber

December 15, 2005
Author(s)
Jingyun Fan, Alan L. Migdall, L Wang
We report efficient generation of correlated photon pairs through degenerate four-wave mixing in a microstructure fiber. With 735.7 nm pump pulses producing correlated signal (688.5 nm) and idler (789.8 nm) photons in a 1.8 m microstructure fiber, we

Efficient Generation of Correlated Photon Pairs in a Microstructure Fiber

December 15, 2005
Author(s)
Jingyun Fan, Alan L. Migdall, L Wang
We report efficient generation of correlated photon pairs through degenerate four-wave mixing in microstructure fibers. With 735.7 nm pump pulses producing conjugate signal (688.5 nm) and idler (789.8 nm) photons in an 1.8 m microstructure fiber, we detect

On-demand Single Photons from Individual Epitaxial Quantum Dots

October 24, 2005
Author(s)
Richard P. Mirin, Martin J. Stevens
We will describe our group's efforts to use epitaxial InGaAs/GaAs quantum dots as sources of on-demand single photons and indistinguishable single photons. We have demonstrated second order intensity correlation measurements, g 2τ, with g 2(0) as low as 0

Criteria for Exact Qudit Universality

October 1, 2005
Author(s)
Stephen Bullock, G K. Brennen, Dianne M. O'Leary
The n-qubit concurrence canonical decomposition (CCD) is a generalization of the two-qubit canonical decomposition SU(4)=[SU(2) (x) SU(2)] ? [SU(2) (x) SU(2)], where ? is the commutative group which phases the maximally entangled Bell basis. A prequel

Enhanced Quantum State Detection Efficiency Through Quantum Information Processing

October 1, 2005
Author(s)
T Schaetz, M D. Barrett, D. Leibfried, J. Britton, J. Chiaverini, W M. Itano, J. D. Jost, Emanuel Knill, C. Langer, David J. Wineland
The n-qubit concurrence canonical decomposition (CCD) is a generalization of the two-qubit canonical decomposition SU(4)=[SU(2) (x) SU(2)] ? [SU(2) (x) SU(2)], where ? is the commutative group which phases the maximally entangled Bell basis. A prequel

Quantum Computing with Realistically Noisy Devices

October 1, 2005
Author(s)
Emanuel H. Knill
There are quantum algorithms that can efficiently simulate quantum physics, factor large numbers and estimate integrals. As a result, quantum computers can solve otherwise intractable computational problems. One of the main problems of experimental quantum

Stability of Global Entanglement in Thermal States of Spin Chains

October 1, 2005
Author(s)
Stephen Bullock, G K. Brennen
The n-qubit concurrence canonical decomposition (CCD) is a generalization of the two-qubit canonical decomposition SU(4)=[SU(2) (x) SU(2)] ? [SU(2) (x) SU(2)], where ? is the commutative group which phases the maximally entangled Bell basis. A prequel

High resolution, high collection efficiency in numerical aperture increasing lens microscopy of individual quantum dots

August 9, 2005
Author(s)
Zhiheng H. Liu, B. B. Goldberg, Stephen B. Ippolito, Anthony N. Vamivakas, M. S. Unlu, Richard Mirin
We demonstrate the application of a subsurface solid immersion technique to the photoluminescence spectroscopy of individual quantum dots. Contrasted with the conventional solid immersion microscopy, we used a numerical aperture increasing lens and moved

Implementation of the Semiclassical Quantum Fourier Transform in a Scalable System

May 1, 2005
Author(s)
J. Chiaverini, J. Britton, D. Leibfried, Emanuel Knill, M D. Barrett, R. B. Blakestad, W M. Itano, J. D. Jost, C. Langer, R Ozeri, T Schaetz, D Britton, David J. Wineland
The n-qubit concurrence canonical decomposition (CCD) is a generalization of the two-qubit canonical decomposition SU(4)=[SU(2) (x) SU(2)] ? [SU(2) (x) SU(2)], where ? is the commutative group which phases the maximally entangled Bell basis. A prequel

Liquid-state NMR Simulations of Quantum Many-body Problems

April 1, 2005
Author(s)
C. Negrevergne, Rolando Somma, Gerardo Ortiz, Emanuel Knill, R. Laflamme
The n-qubit concurrence canonical decomposition (CCD) is a generalization of the two-qubit canonical decomposition SU(4)=[SU(2) (x) SU(2)] ? [SU(2) (x) SU(2)], where ? is the commutative group which phases the maximally entangled Bell basis. A prequel

Matrix Decompositions and Quantum Circuit Design

December 1, 2004
Author(s)
Stephen Bullock
The n-qubit concurrence canonical decomposition (CCD) is a generalization of the two-qubit canonical decomposition SU(4)=[SU(2) (x) SU(2)] ? [SU(2) (x) SU(2)], where ? is the commutative group which phases the maximally entangled Bell basis. A prequel

Realization of Quantum Error Correction

December 1, 2004
Author(s)
J. Chiaverini, D. Leibfried, T Schaetz, M D. Barrett, R. B. Blakestad, J. Britton, W M. Itano, J. D. Jost, Emanuel Knill, C. Langer, R Ozeri, David J. Wineland
The n-qubit concurrence canonical decomposition (CCD) is a generalization of the two-qubit canonical decomposition SU(4)=[SU(2) (x) SU(2)] ? [SU(2) (x) SU(2)], where ? is the commutative group which phases the maximally entangled Bell basis. A prequel
Displaying 826 - 850 of 871