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

429 works between 1991 and 2025
All (429) Journal Article (325) Book Chapter (7) Conference Publication (87) Book (2) Other Outputs (8)

341 - 360 of 429 works

2003

Journal Article

Biased EPR entanglement and its application to teleportation

Bowen, W. P., Lam, P. K. and Ralph, T. C. (2003). Biased EPR entanglement and its application to teleportation. Journal of Modern Optics, 50 (5), 801-813. doi: 10.1080/095003402101522620

Biased EPR entanglement and its application to teleportation

2003

Conference Publication

Quantum computation based on linear optics

Ralph, T. C., Munro, W. J. and Milburn, G. J. (2003). Quantum computation based on linear optics. Quantum Optics in Computing and Communications, Shanghai, China, 16 October 2002. Bellingham, USA: SPIE. doi: 10.1117/12.483016

Quantum computation based on linear optics

2003

Journal Article

Unity and non-unity gain quantum teleportation

Bowen, W. P., Treps, N., Buchler, B. C., Schnabel, R., Ralph, T. C., Symul, T. and Lam, P. K. (2003). Unity and non-unity gain quantum teleportation. IEEE journal of selected topics in quantum electronics, 9 (6), 1519-1532. doi: 10.1109/JSTQE.2003.820908

Unity and non-unity gain quantum teleportation

2003

Journal Article

Comparison of linear optics quantum-computation control-sign gates with ancilla inefficiency and an improvement to functionality under these conditions

Lund, A. P., Bell, T. B. and Ralph, T. C. (2003). Comparison of linear optics quantum-computation control-sign gates with ancilla inefficiency and an improvement to functionality under these conditions. Physical Review A, 68 (2) 022313, 022313-1-022313-16. doi: 10.1103/PhysRevA.68.022313

Comparison of linear optics quantum-computation control-sign gates with ancilla inefficiency and an improvement to functionality under these conditions

2003

Journal Article

Continuous variable polarization entanglement, experiment and analysis

Bowen, W. P., Treps, N., Schnabel, R., Ralph, T. C. and Lam, P. K. (2003). Continuous variable polarization entanglement, experiment and analysis. Journal of Optics B: Quantum and Semiclassical Optics, 5 (4), S467-S478. doi: 10.1088/1464-4266/5/4/352

Continuous variable polarization entanglement, experiment and analysis

2003

Conference Publication

Quantum information processing with Schrodinger cats

Nemoto, K., Gilchrist, A. G., Munro, W. J., Ralph, T. C., Braunstein, S. L. and Milburn, G. J. (2003). Quantum information processing with Schrodinger cats. Fluctuations and Noise in Photonics and Quantum Optics, Santa Fe, NM, USA, 2 June, 2003. Bellingham, USA: SPIE. doi: 10.1117/12.497230

Quantum information processing with Schrodinger cats

2003

Journal Article

Quantum theory of the far-off-resonance continuous-wave Raman laser: Heisenberg-Langevin approach

Roos, P. A., Murphy, S. K., Meng, L. S., Carlsten, J. L., Ralph, T. C., White, A. G. and Brasseur, J. K. (2003). Quantum theory of the far-off-resonance continuous-wave Raman laser: Heisenberg-Langevin approach. Physical Review A - Atomic, Molecular, and Optical Physics, 68 (1). doi: 10.1103/PhysRevA.68.013802

Quantum theory of the far-off-resonance continuous-wave Raman laser: Heisenberg-Langevin approach

2003

Book Chapter

Quantum key distribution with continuous variable in optics

Ralph, T. C. (2003). Quantum key distribution with continuous variable in optics. Quantum Information with Continuous Variables. (pp. 295-316) edited by Samuel L. Braunstein and Arun K. Pati. Netherlands: Kluwer Academic Publishers. doi: 10.1007/978-94-015-1258-9_21

Quantum key distribution with continuous variable in optics

2003

Conference Publication

Optical squeezing in temporal, polarization, and spatial domains

Symul, T., Bowen, W. P., Schnabel, R., Treps, N., Buchler, B. C., Ralph, T. C., Lance, A. M., Grosse, N. B., Dolinska, A., Wu, J. W., Gao, J. R., Fabre, C., Bachor, H.-A. and Lam, P. K. (2003). Optical squeezing in temporal, polarization, and spatial domains. Fluctuations and Noise in Photonics and Quantum Optics II, Santa Fe, NM, USA, 2nd June, 2003. Bellingham, USA: SPIE. doi: 10.1117/12.497081

Optical squeezing in temporal, polarization, and spatial domains

2003

Journal Article

Teleportation of continuous-variable polarization states

Dolinska, A., Buchler, B. C., Bowen, W. P., Ralph, T. C. and Lam, P. K. (2003). Teleportation of continuous-variable polarization states. Physical Review A, 68 (5) 052308, 052308-1-052308-8. doi: 10.1103/PhysRevA.68.052308

Teleportation of continuous-variable polarization states

2003

Conference Publication

Experimental linear optics controlled-NOT gates

Pryde G.J., O'Brien J.L.O., White A.G., Ralph T.C., Bell T.B., Langford N.K. and Milburn G.J. (2003). Experimental linear optics controlled-NOT gates. European Quantum Electronics Conference, EQEC 2003, Munich, , June 22, 2003-June 27, 2003. Institute of Electrical and Electronics Engineers Inc.. doi: 10.1109/EQEC.2003.1314242

Experimental linear optics controlled-NOT gates

2003

Journal Article

Comparison of linear optics quantum-computation control-sign gates with ancilla inefficiency and an improvement to functionality under these conditions

Lund, A. P., Bell, T. B. and Ralph, T. C. (2003). Comparison of linear optics quantum-computation control-sign gates with ancilla inefficiency and an improvement to functionality under these conditions. Physical Review A - Atomic, Molecular, and Optical Physics, 68 (2). doi: 10.1103/PhysRevA.68.022313

Comparison of linear optics quantum-computation control-sign gates with ancilla inefficiency and an improvement to functionality under these conditions

2003

Conference Publication

Efficient linear optics quantum computation

Milburn, G.J., Ralph, T., Gilchrist, A., White, A., Munro, W.J. and Kendon, V (2003). Efficient linear optics quantum computation. 6th International Conference on Quantum Communication, Measurement and Computing (QCMC 02), Cambridge, MA, United States, 22-26 July 2002. Princeton, NJ, United States: Rinton Press.

Efficient linear optics quantum computation

2003

Journal Article

Experimental investigation of criteria for continuous variable entanglement

Bowen, W. P., Schnabel, R., Lam, P. K. and Ralph, T. C. (2003). Experimental investigation of criteria for continuous variable entanglement. Physical Review Letters, 90 (4) 043601, 043601-1-043601-4. doi: 10.1103/PhysRevLett.90.043601

Experimental investigation of criteria for continuous variable entanglement

2003

Conference Publication

Optical experiments beyond the quantum limit: Squeezing entanglement and teleportation

Schnabel, R., Bowen, W. P., Treps, N., Buchler, B. C., Ralph, T. C., Lam, P. K. and Bachor, H. A. (2003). Optical experiments beyond the quantum limit: Squeezing entanglement and teleportation. Russian Federation: Optical Society of America. doi: 10.1134/1.1576832

Optical experiments beyond the quantum limit: Squeezing entanglement and teleportation

2002

Journal Article

Coherent superposition states as quantum rulers

Ralph, T. C. (2002). Coherent superposition states as quantum rulers. Physical Review A, 65 (042313) 042313, 042313-1-042313-4. doi: 10.1103/PhysRevB.65.042313

Coherent superposition states as quantum rulers

2002

Other Outputs

Phase Estimation as a Quantum Nondemolition Measurement

Travaglione, B. C., Milburn, Gerard J. and Ralph, T. C. (2002). Phase Estimation as a Quantum Nondemolition Measurement.

Phase Estimation as a Quantum Nondemolition Measurement

2002

Journal Article

Linear optical controlled-NOT gate in the coincidence basis

Ralph, T. C., Langford, N. K., Bell, T. B. and White, A. G. (2002). Linear optical controlled-NOT gate in the coincidence basis. Physical Review A - Atomic, Molecular, and Optical Physics, 65 (6). doi: 10.1103/PhysRevA.65.062324

Linear optical controlled-NOT gate in the coincidence basis

2002

Journal Article

Separating the quantum sidebands of an optical field

Huntington, EH and Ralph, TC (2002). Separating the quantum sidebands of an optical field. Journal of Optics B-quantum And Semiclassical Optics, 4 (2), 123-128. doi: 10.1088/1464-4266/4/2/307

Separating the quantum sidebands of an optical field

2002

Journal Article

Unconditional continuous-variable dense coding

Ralph, T. C. and Huntington, E.H. (2002). Unconditional continuous-variable dense coding. Physical Review A, 66 (042321) 042321, 042321-1-042321-4. doi: 10.1103/PhysRevA.66.042321

Unconditional continuous-variable dense coding

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

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

Need help?

For help with finding experts, story ideas and media enquiries, contact our Media team:

communications@uq.edu.au