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

434 works between 1991 and 2025
All (434) Journal Article (329) Book Chapter (7) Conference Publication (88) Book (2) Other Outputs (8)

221 - 240 of 434 works

2009

Journal Article

Simplifying quantum logic using higher-dimensional Hilbert spaces

Lanyon, Benjamin P., Barbieri, Marco, Almeida, Marcelo P., Jennewein, Thomas, Ralph, Timothy C., Resch, Kevin J., Pryde, Geoff J., O'Brien, Jeremy L., Gilchrist, Alexei and White, Andrew G. (2009). Simplifying quantum logic using higher-dimensional Hilbert spaces. Nature Physics, 5 (2), 134-140. doi: 10.1038/NPHYS1150

Simplifying quantum logic using higher-dimensional Hilbert spaces

2009

Journal Article

Violations of Bell's inequality for Gaussian states with homodyne detection and nonlinear interactions

Paternostro, M., Jeong, H. and Ralph, T. C. (2009). Violations of Bell's inequality for Gaussian states with homodyne detection and nonlinear interactions. Physical Review A, 79 (1) 012101, 012101-1-012101-7. doi: 10.1103/PhysRevA.79.012101

Violations of Bell's inequality for Gaussian states with homodyne detection and nonlinear interactions

2009

Conference Publication

Full characterization of quantum optical detectors

Coldenstrodt-Ronge, H. B., Worsley, A. P., Lundeen, J. S., Feito, A., Pregnell, K. L., Silberhorn, Ch., Mosley, P. J., Smith, B. J., Puentes, G., Thomas-Peter, N., Ralph, T. C., Eisert, J., Plenio, M. B. and Walmsley, I. A. (2009). Full characterization of quantum optical detectors. CLEO/Pacific Rim 2009: 8th Pacific Rim Conference on Lasers and Electro-Optics, Shanghai, China, 30 August–3 September, 2009. Piscataway, NJ, USA: IEEE. doi: 10.1109/CLEOPR.2009.5292056

Full characterization of quantum optical detectors

2009

Journal Article

Space-quest: experiments with quantum entanglement in space

Ursin, R., Jennewein, T., Kofler, J., Perdigues, J. M., Cacciapuoti, L., de Matos, C. J., Aspelmeyer, M., Valencia, A., Scheidl, T., Acin, A., Barbieri, C., Bianco, G., Brukner, C., Capmany, J., Cova, S., Giggenbach, D., Leeb, W., Hadfield, R. H., Laflamme, R., Lutkenhaus, N., Milburn, G., Peev, M., Ralph, T., Rarity, J., Renner, R., Samain, E., Solomos, N., Tittel, W., Torres, J. P. ... Zeilinger, A. (2009). Space-quest: experiments with quantum entanglement in space. Europhysics News, 40 (3), 26-29. doi: 10.1051/epn/2009503

Space-quest: experiments with quantum entanglement in space

2009

Conference Publication

Nondeterministic noiseless linear amplification of quantum systems

Ralph, T. C. and Lund, A. P. (2009). Nondeterministic noiseless linear amplification of quantum systems. Quantum Communication, Measurement and Computing (QCMC): Ninth International Conference on QCMC, Calgary, Canada, 19-24 August 2008. United States: American Institute of Physics. doi: 10.1063/1.3131295

Nondeterministic noiseless linear amplification of quantum systems

2009

Book Chapter

Optical quantum computation

Ralph, Tim C. and Pryde, Geoff J. (2009). Optical quantum computation. Progress in optics. (pp. 209-269) edited by Emil Wolf. Oxford, United Kingdom: Elsevier. doi: 10.1016/S0079-6638(10)05409-0

Optical quantum computation

2009

Journal Article

Tomography of quantum detectors

Lundeen, J. S., Feito, A., Coldenstrodt-Ronge, H., Pregnell, K. L., Silberhorn, C., Ralph, T. C., Eisert, J., Plenio, M. B. and Walmsley, I. A. (2009). Tomography of quantum detectors. Nature Physics, 5 (1), 27-30. doi: 10.1038/NPHYS1133

Tomography of quantum detectors

2009

Conference Publication

Noiseless linear amplification and distillation of entanglement

Xiang, G. Y., Ralph, T. C., Lund, A. P., Walk, N. and Pryde, Geoff J. (2009). Noiseless linear amplification and distillation of entanglement. ACOLS ACOFT 09, The University of Adelaide, 29/11/09 -3/12/09. South Australia: The University of Adelaide.

Noiseless linear amplification and distillation of entanglement

2008

Journal Article

Teleportation using squeezed single photons

Branczyk, Agata M. and Ralph, T. C. (2008). Teleportation using squeezed single photons. Physical Review A, 78 (5) 052304, 052304-1-052304-8. doi: 10.1103/PhysRevA.78.052304

Teleportation using squeezed single photons

2008

Journal Article

Proposal for optical parity state re-encoder

Gong, Y.-X., Hayes, A.J.F., Guo, G.-C. and Ralph, T.C. (2008). Proposal for optical parity state re-encoder. Journal of Modern Optics, 55 (15), 2415-2428. doi: 10.1080/09500340802130720

Proposal for optical parity state re-encoder

2008

Journal Article

Entangled non-Gaussian states formed by mixing Gaussian states

Lund, A., Ralph, T.C. and van Loock, P. (2008). Entangled non-Gaussian states formed by mixing Gaussian states. Journal of Modern Optics, 55 (13), 2083-2094. doi: 10.1080/09500340801986932

Entangled non-Gaussian states formed by mixing Gaussian states

2008

Journal Article

Methods for a linear optical quantum Fredkin gate

Gong, Yan-Xiao, Guo, Guang-Can and Ralph, Timothy C. (2008). Methods for a linear optical quantum Fredkin gate. Physical Review A (Atomic, Molecular and Optical Physics), 78 (1) 012305, 012305-1-012305-5. doi: 10.1103/PhysRevA.78.012305

Methods for a linear optical quantum Fredkin gate

2008

Journal Article

Single-photon side bands

Ralph, T. C., Huntington, E. H. and Symul, T. (2008). Single-photon side bands. Physical Review A, 77 (6) 063817. doi: 10.1103/PhysRevA.77.063817

Single-photon side bands

2008

Journal Article

Quantum cloning of continuous-variable entangled states

Weedbrook, Christian, Grosse, Nicolai B., Symul, Thomas, Lam, Ping Koy and Ralph, Timothy C. (2008). Quantum cloning of continuous-variable entangled states. Physical Review A, 77 (5) 052313. doi: 10.1103/PhysRevA.77.052313

Quantum cloning of continuous-variable entangled states

2008

Journal Article

Fault-Tolerant Linear Optical Quantum Computing with Small-Amplitude Coherent States

Lund, A. P., Ralph, T. C. and Haselgrove, H. L. (2008). Fault-Tolerant Linear Optical Quantum Computing with Small-Amplitude Coherent States. Physical Review Letters, 100 (3) 030503, 030503-1-030503-4. doi: 10.1103/PhysRevLett.100.030503

Fault-Tolerant Linear Optical Quantum Computing with Small-Amplitude Coherent States

2008

Journal Article

Loss-tolerant operations in parity-code linear optics quantum computing

Hayes, A. J. F., Gilchrist, A. and Ralph, T. C. (2008). Loss-tolerant operations in parity-code linear optics quantum computing. Physical Review A, 77 (1) 012310, 012310-1-012310-8. doi: 10.1103/PhysRevA.77.012310

Loss-tolerant operations in parity-code linear optics quantum computing

2008

Conference Publication

Quantum optical adaptive phase estimation of sidebands

Wheatley, T. A., Huntington, E. H., Berry, D. W., Wiseman, H. M. and Ralph, T. C. (2008). Quantum optical adaptive phase estimation of sidebands. Conference on and Quantum Electronics and Laser Science Conference Lasers and Electro-Optics, QELS 2008, San Jose, CA, 4 - 9 May 2008. Piscataway, NJ United States: I E E E. doi: 10.1109/QELS.2008.4553149

Quantum optical adaptive phase estimation of sidebands

2008

Conference Publication

The CHSH-bell inequality and Tsirelson's bound with postselection

Berry, D. W., Hyunseok, J., Stobinska, M. and Ralph, T. C. (2008). The CHSH-bell inequality and Tsirelson's bound with postselection. Conference on and Quantum Electronics and Laser Science Conference Lasers and Electro-Optics, QELS 2008, San Jose, CA, 4 - 9 May 2008. Piscataway, NJ United States: I E E E. doi: 10.1109/QELS.2008.4553020

The CHSH-bell inequality and Tsirelson's bound with postselection

2008

Journal Article

Practical effects in the preparation of cluster states using weak non-linearities

Rohde, Peter P., Munro, William J., Ralph, Timothy C., van Loock, Peter and Nemoto, Kae (2008). Practical effects in the preparation of cluster states using weak non-linearities. Quantum Information & Computation, 8 (1 & 2), 0053-0067.

Practical effects in the preparation of cluster states using weak non-linearities

2007

Conference Publication

The quantum noise limits to simultaneous intensity and frequency stabilization of solid-state lasers

Huntington, E. H., Harb, C. C., Heurs, M. and Ralph, T. C. (2007). The quantum noise limits to simultaneous intensity and frequency stabilization of solid-state lasers. 2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference, CLEO, , , June 17, 2007-June 22, 2007. NEW YORK: Optical Society of America. doi: 10.1109/CLEO.2007.4453689

The quantum noise limits to simultaneous intensity and frequency stabilization of solid-state lasers

Current funding

  • 2024 - 2027
    Deployable Quantum Relay (DSP Multi-Party Collaborative Project led by Griffith University)
    Commonwealth Defence Science and Technology Group
    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

  • 2023 - 2025
    Quantum Communications with Continuous Variables (UNSW subcontract agreement)
    University of New South Wales
    Open grant
  • 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 - 2009
    Theoretical studies in quantum information
    Department Defence - Defence Science & Technology
    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

    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

    Beyond quantum field theory on a curved background

    Principal Advisor

  • Master Philosophy

    Resolving paradoxes of closed timelike curves

    Principal Advisor

  • Doctor Philosophy

    Quantum information processing with linear optics

    Principal Advisor

  • Doctor Philosophy

    Demonstration of relativistic Bohmian trajectories of photons

    Associate Advisor

    Other advisors: 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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