120 likes | 379 Views
RAMBOQ: highlights http://www.RAMBOQ.org. Bratislava, Feb 16 th 2004. Abstract. We will explore the possibility of building scalable quantum information processors using linear quantum logic.
E N D
RAMBOQ: highlightshttp://www.RAMBOQ.org Bratislava, Feb 16th 2004
Abstract We will explore the possibility of building scalable quantum information processors using linear quantum logic. Includes probabilistic CNOT gates assembled from single photon sources and sources of entangled states. Investigate the development of higher dimensional quantum logic aimed at developing error resilient quantum networks. Develop more efficient detectors and practical single and multi-photon sources suitable for logic realisations. A theoretical effort will aim to increase the efficiency of simple gates and look at scalability, error correction and the overall limits to this technology.
Partners P01: E & EE Department, University of Bristol, UK (UoB) P02: Toshiba Research Europe Limited, Cambridge, UK (TREL) P03: Hewlett Packard European Laboratories, UK (HPLB) P04: University of Queensland, Centre for Quantum Computer Technology, Australia (UQ) P05: Group of Applied Physics, University of Geneva, Switz (GAP) P06: Institut Fuer Experimentalphysik, Universitaet Wien, Austria (UniVie) P07: Sektion Physik, Ludwig-Maximillians-Universität, Munchen,De (LMU) P08: University of Cambridge, Department of Physics (CAM) P09: Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) P10: Id Quantique, Geneva, Switzerland. (IDQ) P11: THALES Research and Technology (TRT) P12: INFM/LONO at the University of Rome III (INFM/LONO) P13: Quantum Phenomena and Materials, University of Paris 7 (QPM) Project Internet site: http://www.ramboq.org
Work packages WP0 Management and dissemination of results, UoB +all WP1 Theory of linear quantum logic HP/UQ/FAU WP2 Input-output: single photon and entangled pair sources and detectors TREL/UoB/IDQ/GAP/TRT/INFM/LONO/QPM WP3 Implementation of quantum logic. UNIVIE/ UoB/LMU/TREL WP4 Tools for Quantum Networks: LMU/GAP/UNIVIE WP5 Higher dimensional Hilbert space GAP/UNIVIE/LMU WP6 Applications UoB + all
WP1 CNOT, CS gates, input state requirements, limits to projective measurements (HP, UQ, UniVie, UoB, FAU) A. Gilchrist, W.J. Munro, A.G. White, Phys. Rev. A 67, 040304R (2003) K. Sanaka, K. Resch, quant-ph/0312226 S. Scheel, Kae Nemoto, W. J. Munro, P. L. Knight, Phys. Rev. A 68, 032310 (2003) P. van Loock and N. Lütkenhaus, in press PRA, quant-ph/0304057 J.Rarity: Royal Society Philosophical Transactions 361, 2003, 1507-18
Demonstration of a single photon quantum dot source in a microcavity (WP2, TREL, UoB) Micropillar microcavity light sources containing single quantum dots. Enhanced emission from single mode leads to reduced lifetime (Purcell factor of 4). These are true single photon sources (g(2)=0) with external efficiency ~10%. FDTD and mode Solver simulations
WP1,3 Experimental Demonstration of Nonlinear Sign-Shift Gate (UniVie) • (a) Set-up for observing NS shift (b) Four-fold as function of position delay. (c) Four-fold as function of relative phase. Sanaka, Jennewein, Pan, Resch, Zeilinger, PRL 92, 017902 (2004).
WP4: Quantum relay We have implemented a quantum relay by quantum teleportation relay increases maximum communication distancehere: transmission distance 6 km
three-photon entanglement residual state dependson measurement result WP3,4: Three-photon W-state (LMU) use linear optics quantum interference to observe multi-party states
WP5: ExperimentalQutritCHSH Test16 x 16 x 16 x 16 Correlations (UniVie) Brute Force Attack • 4-axis scan of horizontal hologram positions • Look for violation of qutrit inequality in scan data Exp. Max = 2.90 ± 0.05 QT Max = 2.87 A.Vaziri,G. Weihs, A. Zeilinger Phys. Rev. Lett. 89, 240401(2002)
Futures: what we are aiming for.... • High efficiency detectors for single and multiple photons. • Time bandwidth limited single photons on demand (??done). • Entangled photon pairs on demand (waveguides and Qdots). • Linear gates with high efficiency and low errors (started). • Entanglement and single photons for scalable high efficiency gates. • High dimension entanglement and analysis (novel protocols). • Use of high-D Q-Nits in QIP. • Inter-conversion to/from solid state Qubits: • Storage of Qbits (solid state) • Manipulation (phase gates)