Professor Timothy Ralph
Professor

Timothy Ralph

Email: 
Phone: 
+61 7 334 69693

Background

Professor Ralph obtained a BSc Hons from Macquarie University in 1989 and a PhD in Physics from The Australian National University in 1993. He has held three Australian Research Council Fellowships - Postdoctoral, QEII and Professorial. He is currently Node Director for the ARC Centre of Excellence for Quantum Computation and Communication Technology at the University of Queensland.

Availability

Professor Timothy Ralph is:
Available for supervision
Media expert

Fields of research

Physical Sciences

Qualifications

  • Bachelor (Honours) of Science (Advanced), Macquarie University
  • Doctor of Philosophy, Australian National University

Research interests

  • Linear Optics Quantum Computation.

    As part of the Centre for Quantum Computation and Communication Technology we are attempting to understand and implement simple quantum gates using the techniques of linear optics and measurement induced state projection.

  • Quantum Communication with Lasers.

    Quantum information techniques allow one to communicate with absolute security, amongst other applications. As part of the Centre for Quantum Computation and Communication Technology we are developing such secure communication protocols based on sending coherent states of light and measuring their amplitudes.

  • Relativistic Quantum Information.

    This project examines the interface between quantum mechanics, general relativity and information theory. It asks, both at a fundamental and practical level, what the ramifications for quantum information theory are when space-time curvature and rapid motion are introduced.

Search Professor Timothy Ralph’s works on UQ eSpace

430 works between 1991 and 2025
All (430) Journal Article (326) Book Chapter (7) Conference Publication (87) Book (2) Other Outputs (8)

241 - 260 of 430 works

2007

Journal Article

Photon number projection using non-number-resolving detectors

Rohde, Peter P., Webb, James G., Huntington, Elanor H. and Ralph, Timothy C. (2007). Photon number projection using non-number-resolving detectors. New Journal of Physics, 9 (233) 233, 010233-1-010233-18. doi: 10.1088/1367-2630/9/7/233

Photon number projection using non-number-resolving detectors

2007

Journal Article

Optical zeno gate: Bounds for fault tolerant operation

Leung, P. M. and Ralph, T. C. (2007). Optical zeno gate: Bounds for fault tolerant operation. New Journal of Physics, 9 (7) 224, 010224-1-010224-10. doi: 10.1088/1367-2630/9/7/224

Optical zeno gate: Bounds for fault tolerant operation

2007

Journal Article

Efficient parity-encoded optical quantum computing

Gilchrist, Alexei, Hayes, A. J. F. and Ralph, T. C. (2007). Efficient parity-encoded optical quantum computing. Physical Review A, 75 (052328) 052328, 052328-1-052328-5. doi: 10.1103/PhysRevA.75.052328

Efficient parity-encoded optical quantum computing

2007

Journal Article

Observation of a comb of optical squeezing over many gigahertz of bandwidth

Senior, R. J., Milford, G. N., Janousek, J., Dulop, A. E., Wagner, K., Bachor, H. -A., Ralph, Timothy C., Huntington, E. H. and Harb, C. C. (2007). Observation of a comb of optical squeezing over many gigahertz of bandwidth. Optics Express, 15 (9), 5310-5317. doi: 10.1364/OE.15.005310

Observation of a comb of optical squeezing over many gigahertz of bandwidth

2007

Journal Article

Measuring Photon Antibunching from Continuous Variable Sideband Squeezing

Grosse, N. B., Symul, T., Stobinska, M., Ralph, T. C. and Lam, P. K. (2007). Measuring Photon Antibunching from Continuous Variable Sideband Squeezing. Physical Review Letters, 98 (15) 153603, 153603-1-153603-4. doi: 10.1103/PhysRevLett.98.153603

Measuring Photon Antibunching from Continuous Variable Sideband Squeezing

2007

Journal Article

Efficient Toffoli gates using qudits

Ralph, T. C., Resch, K. J. and Gilchrist, A. (2007). Efficient Toffoli gates using qudits. Physical Review A, 75 (2) 022313, 022313-1-022313-5. doi: 10.1103/PhysRevA.75.022313

Efficient Toffoli gates using qudits

2007

Journal Article

Quantum and classical fidelities for Gaussian states

Jeong, Hyunseok, Ralph, Timothy C. and Bowen, Warwick P. (2007). Quantum and classical fidelities for Gaussian states. Journal of The Optical Society of America B - Optical Physics, 24 (2), 355-362. doi: 10.1364/JOSAB.24.000355

Quantum and classical fidelities for Gaussian states

2007

Journal Article

Linear optical quantum computing with photonic qubits

Kok, Pieter, Munro, W. J., Nemoto, K.ae, Ralph, T. C.,, Dowling, Jonathon P. and Milburn, G. J. (2007). Linear optical quantum computing with photonic qubits. Reviews of Modern Physics, 79 (1), 135-174. doi: 10.1103/RevModPhys.79.135

Linear optical quantum computing with photonic qubits

2007

Journal Article

Quantum noise limits to simultaneous quadrature amplitude and phase stabilization of solid-state lasers

Huntington, E. H., Harb, C. C., Heurs, M. and Ralph, T. C. (2007). Quantum noise limits to simultaneous quadrature amplitude and phase stabilization of solid-state lasers. Physical Review A, 75 (1) 013802, 013802-1-013802-8. doi: 10.1103/PhysRevA.75.013802

Quantum noise limits to simultaneous quadrature amplitude and phase stabilization of solid-state lasers

2007

Conference Publication

Improving fidelity of skewed output states of optical zeno gates

Leung P.M. and Ralph T.C. (2007). Improving fidelity of skewed output states of optical zeno gates. 2007 Quantum Electronics and Laser Science Conference, QELS, Baltimore, MD, May 6, 2007-May 11, 2007. doi: 10.1109/QELS.2007.4431700

Improving fidelity of skewed output states of optical zeno gates

2007

Journal Article

Error tolerance and tradeoffs in loss- and failure-tolerant quantum computing schemes

Rohde, Peter P., Ralph, Timothy C. and Munro, William J. (2007). Error tolerance and tradeoffs in loss- and failure-tolerant quantum computing schemes. Physical Review A, 75 (1) 010302, 010302-1-010302-4. doi: 10.1103/PhysRevA.75.010302

Error tolerance and tradeoffs in loss- and failure-tolerant quantum computing schemes

2007

Conference Publication

Can gravitational curvature induce decorrelation of optical entanglement

Downes, T., Milburn, G. J. and Ralph, T. C. (2007). Can gravitational curvature induce decorrelation of optical entanglement. Quantum Communications and Quantum Imaging V, San Diego, USA, 26 August 2007. BELLINGHAM: SPIE-INT SOC OPTICAL ENGINEERING. doi: 10.1117/12.740085

Can gravitational curvature induce decorrelation of optical entanglement

2007

Journal Article

Violation of Bell's inequality using classical measurements and nonlinear local operations

Stobinska, Magdalena, Jeong, Hyunseok and Ralph, Timothy C. (2007). Violation of Bell's inequality using classical measurements and nonlinear local operations. Physical Review A, 75 (5) 052105, 052105-1-052105-5. doi: 10.1103/PhysRevA.75.052105

Violation of Bell's inequality using classical measurements and nonlinear local operations

2007

Book Chapter

Schrödinger cat states for quantum information processing

Jeong, Hyunseok and Ralph, Timothy C. (2007). Schrödinger cat states for quantum information processing. Quantum Information with Continuous Variables of Atoms and Light. (pp. 159-180) Imperial College Press. doi: 10.1142/9781860948169_0009

Schrödinger cat states for quantum information processing

2007

Conference Publication

Measuring photon anti-bunching from sideband squeezing with continuous-variable techniques

Grosse N.B., Symul T., Stobinska M., Ralph T.C. and Lam P.K. (2007). Measuring photon anti-bunching from sideband squeezing with continuous-variable techniques. 2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference, CLEO, Munich, June 17, 2007-June 22, 2007. Optical Society of America. doi: 10.1109/CLEOE-IQEC.2007.4386953

Measuring photon anti-bunching from sideband squeezing with continuous-variable techniques

2007

Conference Publication

Continuous variable quantum cryptography: Post-selection with thermal noise

Assad S., Alton D.J., Symul T., Lam P.K., Weedbrook C. and Ralph T. (2007). Continuous variable quantum cryptography: Post-selection with thermal noise. 2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference, CLEO, Munich, June 17, 2007-June 22, 2007. doi: 10.1109/CLEOE-IQEC.2007.4386770

Continuous variable quantum cryptography: Post-selection with thermal noise

2007

Conference Publication

Schrodinger cat states for quantum information processing

Jeong, Hyunseok and Ralph, Timothy C. (2007). Schrodinger cat states for quantum information processing. Quantum Information Processing and Communication Workshop, Prague Czech Republic, 2005. COVENT GARDEN: IMPERIAL COLL PRESS. doi: 10.1142/9781860948169_0009

Schrodinger cat states for quantum information processing

2007

Book Chapter

Schrodinger Cat States for Quantum Information Processing

Jeong, H. and Ralph, T. C. (2007). Schrodinger Cat States for Quantum Information Processing. Quantum Information with Continuous Variables of Atoms and Light. (pp. 159-177) edited by Nicolas J. Cerf, Gerd Leuchs and Eugene S. Polzik. London: Imperial College Press.

Schrodinger Cat States for Quantum Information Processing

2006

Journal Article

Universal quantum computation with continuous-variable cluster states

Menicucci, Nicolas C., van Loock,, Peter, Gu, Mile, Weedbrook, Christian, Ralph, Timothy C. and Nielsen, Michael A. (2006). Universal quantum computation with continuous-variable cluster states. Physical Review Letters, 97 (11) 110501, 110501-1-110501-4. doi: 10.1103/PhysRevLett.97.110501

Universal quantum computation with continuous-variable cluster states

2006

Journal Article

Quantum memory scheme based on optical fibers and cavities

Leung, Patrick M. and Ralph, Timothy C. (2006). Quantum memory scheme based on optical fibers and cavities. Physical Review A, 74 (2) 022311, 022311-1-022311-6. doi: 10.1103/PhysRevA.74.022311

Quantum memory scheme based on optical fibers and cavities

Current funding

  • 2024 - 2027
    Deployable Quantum Relay (DSP Multi-Party Collaborative Project led by Griffith University)
    Commonwealth Defence Science and Technology Group
    Open grant
  • 2023 - 2025
    Quantum Communications with Continuous Variables (UNSW subcontract agreement)
    University of New South Wales
    Open grant
  • 2018 - 2025
    ARC Centre of Excellence for Quantum Computation and Communication Technology (CQC2T) (ARC Centre of Excellence administered by UNSW)
    University of New South Wales
    Open grant

Past funding

  • 2021 - 2024
    A Space-Based Quantum Communications Platform using Continuous Variables (ARC Linkage Project led by University of NSW)
    University of New South Wales
    Open grant
  • 2019 - 2021
    Enabling quantum information technology with 60 photons and beyond
    United States Asian Office of Aerospace Research and Development
    Open grant
  • 2019 - 2020
    Platform independent studies on optimising quantum repeater architectures (Australian Department of Defence grant administered by QuintessenceLabs Pty Ltd)
    Quintessencelabs Pty Ltd
    Open grant
  • 2017 - 2020
    Quantum Key Distribution (QKD) System
    Quintessencelabs Pty Ltd
    Open grant
  • 2011 - 2018
    ARC Centre of Excellence for Quantum Computation and Communication Technology (ARC COE administered by the University of New South Wales)
    University of New South Wales
    Open grant
  • 2011 - 2013
    Quantum Optics and Quantum Information
    Vice-Chancellor's Senior Research Fellowship
    Open grant
  • 2010
    Quantum memory
    Australian National University
    Open grant
  • 2008 - 2012
    Quantum repeater technologies for continuous variable (ARC Discovery Project DP0879277 administered by ANU)
    Australian National University
    Open grant
  • 2006 - 2010
    Optical Quantum Computation
    ARC Discovery Projects
    Open grant
  • 2003 - 2010
    ARC Centre of Excellence for Quantum Computer Technology (UNSW lead institution)
    ARC Centres of Excellence
    Open grant
  • 2003 - 2005
    Quantum Photonics- Travel Award
    Australian National University
    Open grant
  • 2002 - 2004
    Towards Quantum Computation with Light
    UQ Foundation Research Excellence Awards - DVC(R) Funding
    Open grant
  • 2002 - 2004
    ARC Discovery Project - Quantum Photonics with continuous laser beams
    Australian National University
    Open grant
  • 2001 - 2004
    Experimental Implementation of Efficient Linear Optics Quantum Computation
    United States Army Research Office
    Open grant
  • 2000
    Optical entangler for Quantum Communication
    Australian National University
    Open grant
  • 2000 - 2005
    Quantum Information with Continuous Variables
    ARC Australian Research Fellowship/QEII F/ship
    Open grant
  • 2000
    Quantum information with continuous variables
    UQ New Staff Research Start-Up Fund
    Open grant

Availability

Professor Timothy Ralph is:
Available for supervision

Before you email them, read our advice on how to contact a supervisor.

Available projects

  • Optical Quantum Computation

    As part of the Centre for Quantum Computation and Communication Technology we are attempting to understand and implement optical quantum computation using the techniques of linear optic networks and measurement induced state projection. Projects are available examining intemediate scale protocols and algorithms as well as large scale architectures.

  • Quantum communication with lasers

    Quantum information techniques allow one to communicate with absolute security, amongst other applications. As part of the Centre for Quantum Computation and Communication Technology we are developing such secure communication protocols based on sending coherent and squeezed states of light and measuring their amplitudes. Projects concerning quantum repeaters for extending communication links and satellite to ground quantum communication are available.

  • Relativistic quantum information

    Projects are available that involve examining the interface between quantum mechanics, general relativity and information theory. They ask, both at a fundamental and practical level, what the ramifications for quantum information theory are when space-time curvature, rapid motion and/or very fast transformations are introduced.

Supervision history

Current supervision

  • Doctor Philosophy

    Quantum mechanics near closed timelike curves

    Principal Advisor

  • Doctor Philosophy

    Beyond quantum field theory on a curved background

    Principal Advisor

  • Doctor Philosophy

    Production of quantum communication systems capable of operating onboard low-earth orbit satellites and developing integrated quantum and classical satellite communication protocols.

    Principal Advisor

  • Doctor Philosophy

    Practical applications of quantum sampling algorithms

    Principal Advisor

  • Master Philosophy

    Quantum effects in general relativistic spacetimes

    Principal Advisor

  • Doctor Philosophy

    Production of quantum communication systems capable of operating onboard low-earth orbit satellites and developing integrated quantum and classical satellite communication protocols.

    Principal Advisor

  • Master Philosophy

    Resolving paradoxes of closed timelike curves

    Principal Advisor

  • Doctor Philosophy

    Perspectives on the de Broglie-Bohm interpretation

    Associate Advisor

    Other advisors: Associate Professor Sally Shrapnel, Dr Peter Evans

  • Doctor Philosophy

    Demonstration of relativistic Bohmian trajectories of photons

    Associate Advisor

    Other advisors: Dr Daniel Peace, Associate Professor Jacqui Romero

  • Doctor Philosophy

    Thermodynamic fluctuation relations for gravitating quantum systems

    Associate Advisor

    Other advisors: Dr Carolyn Wood, Dr Laura Henderson

Completed supervision

Enquiries

Contact Professor Timothy Ralph directly for media enquiries about:

  • Laser noise - physics
  • Optics - quantum
  • Physics
  • Quantum information
  • Quantum key distribution with continuous variables
  • Quantum optics
  • Quantum physics
  • Teleportation

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