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)

181 - 200 of 430 works

2011

Journal Article

Engineered optical nonlinearity for a quantum light source

Branczyk, Agata M., Fedrizzi, Alessandro, Stace, Thomas M., Ralph, Tim C. and White, Andrew G. (2011). Engineered optical nonlinearity for a quantum light source. Optics Express, 19 (1), 55-65. doi: 10.1364/OE.19.000055

Engineered optical nonlinearity for a quantum light source

2011

Conference Publication

The Heisenberg picture for single photon states

Pienaar, Jacques, Myers, Casey and Ralph, Timothy C. (2011). The Heisenberg picture for single photon states. 10th International Conference on Quantum Communication, Measurement and Computing (QCMC), Brisbane, Australia, 19-23 July 2010. Melville, NY, United States: American Institute of Physics. doi: 10.1063/1.3630189

The Heisenberg picture for single photon states

2011

Conference Publication

Photon number discrimination without a photon counter and reconstructing non-Gaussian states of light

Chrzanowski, Helen, Bernu, Julien, Sparkes, Ben, Hage, Boris, Lund, Austin, Ralph, Tim, Lam, Ping Koy and Symul, Thomas (2011). Photon number discrimination without a photon counter and reconstructing non-Gaussian states of light. Conference on Lasers and Electro-Optics Pacific Rim, Sydney, Australia, 28 August - 1 September 2011.

Photon number discrimination without a photon counter and reconstructing non-Gaussian states of light

2011

Conference Publication

A functional interpretation of continuous variable quantum discord

Assad, Syed, Chrzanowski, Helen, Symul, Thomas, Lam, Ping Koy, Ralph, Tim, Gu, Mile and Vedral, Vlatko (2011). A functional interpretation of continuous variable quantum discord. IQEC/CLEO Pacific Rim Conference 2011 incorporating ACOLS and ACOFT, Sydney, NSW, Australia, 28 August-1 September, 2011. Piscataway, NJ, United States: Institute of Electrical and Electronics Engineers. doi: 10.1109/IQEC-CLEO.2011.6194178

A functional interpretation of continuous variable quantum discord

2011

Conference Publication

Time ordering in spontaneous parametric down-conversion

Branczyk, Agata M., Stace, Thomas M. and Ralph, T. C. (2011). Time ordering in spontaneous parametric down-conversion. 10th International Conference on Quantum Communication, Measurement and Computing (QCMC), Brisbane, Australia, 19-23 July 2010. Melville, NY, United States: American Institute of Physics. doi: 10.1063/1.3630207

Time ordering in spontaneous parametric down-conversion

2011

Conference Publication

Squeezing-enhanced adaptive optical phase estimation

Yonezawa, Hidehiro, Nakane, Daisuke, Wheatley, Trevor A., Iwasawa, Kohjiro, Takeda, Shuntaro, Arao, Hajime, Berry, Dominic W., Ralph, Timothy C., Wiseman, Howard M., Huntington, Elanor and Furusawa, Akira (2011). Squeezing-enhanced adaptive optical phase estimation. Quantum Electronics and Laser Science Conference (QELS), Baltimore, MD, United States, 1-6 May 2011. Piscataway, NJ, United States: IEEE. doi: 10.1364/QELS.2011.QFD5

Squeezing-enhanced adaptive optical phase estimation

2011

Conference Publication

Schrödinger kitten and cat states characterisation using only continuous variables and Gaussian resources

Chrzanowski, H. M., Symul, T., Bernu, J., Hage, B., Lund, A., Ralph, T. C. and Lam, P. K. (2011). Schrödinger kitten and cat states characterisation using only continuous variables and Gaussian resources. 2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference, CLEO EUROPE/EQEC 2011, Munich, Germany, 22-26 May 2011. Piscataway, NJ United States: IEEE. doi: 10.1109/CLEOE.2011.5943387

Schrödinger kitten and cat states characterisation using only continuous variables and Gaussian resources

2011

Conference Publication

Security of Post-selection based Continuous Variable Quantum Key Distribution against Arbitrary Attacks

Walk, Nathan, Ralph, Timothy C., Symul, Thomas and Lam, Ping Koy (2011). Security of Post-selection based Continuous Variable Quantum Key Distribution against Arbitrary Attacks. Conference on Lasers and Electro-Optics (CLEO), Baltimore Md, May 01-06, 2011. NEW YORK: IEEE. doi: 10.1364/cleo_at.2011.jtuc4

Security of Post-selection based Continuous Variable Quantum Key Distribution against Arbitrary Attacks

2011

Conference Publication

Adaptive optical phase estimation using time-symmetric quantum smoothing

Wheatley, T. A., Berry, D. W., Yonezawa, H., Nakane, D., Arao, H., Pope, D. T., Ralph, T. C., Wiseman, H. M., Furusawa, A. and Huntington, E. H. (2011). Adaptive optical phase estimation using time-symmetric quantum smoothing. 10th International Conference on Quantum Communication, Measurement and Computing (QCMC), Brisbane, Australia, 19-23 July 2010. Melville, NY, United States: American Institute of Physics. doi: 10.1063/1.3630163

Adaptive optical phase estimation using time-symmetric quantum smoothing

2010

Journal Article

Information flow of quantum states interacting with closed timelike curves

Ralph, T. C. and Myers, C. R. (2010). Information flow of quantum states interacting with closed timelike curves. Physical Review A - Atomic, Molecular, and Optical Physics, 82 (6) 062330, 062330-1-062330-5. doi: 10.1103/PhysRevA.82.062330

Information flow of quantum states interacting with closed timelike curves

2010

Journal Article

High-fidelity operation of quantum photonic circuits

Laing, A, Peruzzo, A, Politi, A, Verde, MR, Halder, M, Ralph, TC, Thompson, MG and O'Brien, JL (2010). High-fidelity operation of quantum photonic circuits. Applied Physics Letters, 97 (21) 211109, 211109-1-211109-3. doi: 10.1063/1.3497087

High-fidelity operation of quantum photonic circuits

2010

Journal Article

Quantum cryptography approaching the classical limit

Weedbrook, Christian, Pirandola, Stefano, Lloyd, Seth and Ralph, Timothy C. (2010). Quantum cryptography approaching the classical limit. Physical Review Letters, 105 (11) 110501, 1-4. doi: 10.1103/PhysRevLett.105.110501

Quantum cryptography approaching the classical limit

2010

Journal Article

Fault tolerance in parity-state linear optical quantum computing

Hayes, A. J. F., Haselgrove, H. L., Gilchrist, Alexei and Ralph, T. C. (2010). Fault tolerance in parity-state linear optical quantum computing. Physical Review A, 82 (2) 022323, 022323-1-022323-9. doi: 10.1103/PhysRevA.82.022323

Fault tolerance in parity-state linear optical quantum computing

2010

Journal Article

Optimized generation of heralded Fock states using parametric down-conversion

Brańczyk, Agata M., Ralph, T. C., Helwig, Wolfram and Silberhorn, Christine (2010). Optimized generation of heralded Fock states using parametric down-conversion. New Journal of Physics, 12 (6) 063001, 063001-1-063001-29. doi: 10.1088/1367-2630/12/6/063001

Optimized generation of heralded Fock states using parametric down-conversion

2010

Journal Article

Arbitrarily large continuous-variable cluster states from a single quantum nondemolition gate

Menicucci, NC, Ma, XA and Ralph, TC (2010). Arbitrarily large continuous-variable cluster states from a single quantum nondemolition gate. Physical Review Letters, 104 (25) 250503, 250503-1-250503-4. doi: 10.1103/PhysRevLett.104.250503

Arbitrarily large continuous-variable cluster states from a single quantum nondemolition gate

2010

Journal Article

Linear optical quantum computation with imperfect entangled photon-pair sources and inefficient non-photon-number-resolving detectors

Gong, Yan-Xiao, Zou, Xu-Bo, Ralph, Timothy C., Zhu, Shi-Ning and Guo, Guang-Can (2010). Linear optical quantum computation with imperfect entangled photon-pair sources and inefficient non-photon-number-resolving detectors. Physical Review A, 81 (5) 052303, 052303-1-052303-4. doi: 10.1103/PhysRevA.81.052303

Linear optical quantum computation with imperfect entangled photon-pair sources and inefficient non-photon-number-resolving detectors

2010

Journal Article

Heralded noiseless linear amplification and distillation of entanglement

Xiang, G. Y., Ralph, T. C., Lund, A. P., Walk, N. and Pryde, G. J. (2010). Heralded noiseless linear amplification and distillation of entanglement. Nature Photonics, 4 (5), 316-319. doi: 10.1038/NPHOTON.2010.35

Heralded noiseless linear amplification and distillation of entanglement

2010

Journal Article

Multiplexed communication over a high-speed quantum channel

Heurs, M., Webb, J. G., Dunlop, A. E., Harb, C.C., Ralph, T. C. and Huntington, E. H. (2010). Multiplexed communication over a high-speed quantum channel. Physical Review A - Atomic, Molecular, and Optical Physics, 81 (3) 032325, 032325 -1-032325- 4. doi: 10.1103/PhysRevA.81.032325

Multiplexed communication over a high-speed quantum channel

2010

Journal Article

Adaptive optical phase estimation using time-symmetric quantum smoothing

Wheatley, T. A., Berry, D. W., Yonezawa, H., Nakane, D., Arao, H., Pope, D. T., Ralph, T. C., Wiseman, H. M., Furusawa, A. and Huntington, E. H. (2010). Adaptive optical phase estimation using time-symmetric quantum smoothing. Physical Review Letters, 104 (9) 093601, 093601-1-093601-4. doi: 10.1103/PhysRevLett.104.093601

Adaptive optical phase estimation using time-symmetric quantum smoothing

2010

Journal Article

Fair-sampling assumption is not necessary for testing local realism

Berry, Dominic W., Jeong, Hyunseok, Stobinska, Magdalena and Ralph, Timothy C. (2010). Fair-sampling assumption is not necessary for testing local realism. Physical Review A, 81 (1) 012109, 012109-1-012109-11. doi: 10.1103/PhysRevA.81.012109

Fair-sampling assumption is not necessary for testing local realism

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

    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

    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

    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

  • Doctor Philosophy

    Perspectives on the de Broglie-Bohm interpretation

    Associate Advisor

    Other advisors: Associate Professor Sally Shrapnel, Dr Peter Evans

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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