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)

281 - 300 of 430 works

2005

Conference Publication

Quantum gate characterization in an extended Hilbert space

Rohde, Peter P., Pryde, G. J., O'Brien, J. L. and Ralph, Timothy C. (2005). Quantum gate characterization in an extended Hilbert space. Optical Society of America.

Quantum gate characterization in an extended Hilbert space

2005

Conference Publication

Coherent manipulation of quantum optical sideband modes

Huntington, E. H., Milford, G. N., Robilliard, C. and Ralph, T. C. (2005). Coherent manipulation of quantum optical sideband modes. Optical Society of America. doi: 10.1109/qels.2005.1548743

Coherent manipulation of quantum optical sideband modes

2005

Journal Article

Loss-tolerant optical qubits

Ralph, T. C., Hayes, A. J. F. and Gilchrist, Alexei (2005). Loss-tolerant optical qubits. Physical Review Letters, 95 (10) 100501, 100501-100504. doi: 10.1103/PhysRevLett.95.100501

Loss-tolerant optical qubits

2005

Journal Article

Quantum-gate characterization in an extended Hilbert space (vol 72, pg 032306, 2005)

Rohde, Peter P., Pryde, G. J., O'Brien, J. L. and Ralph, Timothy C. (2005). Quantum-gate characterization in an extended Hilbert space (vol 72, pg 032306, 2005). Physical Review A, 72 (3). doi: 10.1103/PhysRevA.72.039906

Quantum-gate characterization in an extended Hilbert space (vol 72, pg 032306, 2005)

2005

Journal Article

Quantum-gate characterization in an extended Hilbert space

Rohde, P., Pryde, G. J., O'Brien, J. L. and Ralph, T. C. (2005). Quantum-gate characterization in an extended Hilbert space. Physical Review A, 72 (3) 032306, 0323061-0323065. doi: 10.1103/PhysRevA.72.032306

Quantum-gate characterization in an extended Hilbert space

2005

Journal Article

Publisher’s Note: Measurement of Quantum Weak Values of Photon Polarization [Phys. Rev. Lett. 94, 220405 (2005)]

Pryde, G. J., O'Brien, J. L., White, A. G., Ralph, T. C. and Wiseman, H. M. (2005). Publisher’s Note: Measurement of Quantum Weak Values of Photon Polarization [Phys. Rev. Lett. 94, 220405 (2005)]. Physical Review Letters, 94 (23) 239904. doi: 10.1103/PhysRevLett.94.239904

Publisher’s Note: Measurement of Quantum Weak Values of Photon Polarization [Phys. Rev. Lett. 94, 220405 (2005)]

2005

Journal Article

Pryde et al. Reply

Pryde, G. J., O'Brien, J. L., White, A. G., Bartlett, S. D. and Ralph, T. C. (2005). Pryde et al. Reply. Physical Review Letters, 95 (4) 048902, 0489021-0489021. doi: 10.1103/PhysRevLett.95.048902

Pryde et al. Reply

2005

Journal Article

No-switching quantum key distribution using broadband modulated coherent light

Lance, Andrew M., Symul, Thomas, Sharma, Vikram, Weedbrook, Christian, Ralph, Timothy C. and Lam, Ping Koy (2005). No-switching quantum key distribution using broadband modulated coherent light. Physical Review Letters, 95 (18) 180503, 180503-1-180503-4. doi: 10.1103/PhysRevLett.95.180503

No-switching quantum key distribution using broadband modulated coherent light

2005

Journal Article

Coherent analysis of quantum optical sideband modes

Huntington, E. H., Milford, G. N., Robilliard, C. and Ralph, T. C. (2005). Coherent analysis of quantum optical sideband modes. Optics Letters, 30 (18), 2481-2483. doi: 10.1364/OL.30.002481

Coherent analysis of quantum optical sideband modes

2005

Journal Article

Coherent-state linear optical quantum computing gates using simplified diagonal superposition resource states

Lund, A. P. and Ralph, T. C. (2005). Coherent-state linear optical quantum computing gates using simplified diagonal superposition resource states. Physical Review A, 71 (3) 032305, 032305-1-032305-9. doi: 10.1103/PhysRevA.71.032305

Coherent-state linear optical quantum computing gates using simplified diagonal superposition resource states

2005

Conference Publication

Linear optical quantum computation with parity encoding

Gilchrist A., Hayes A.J.F. and Ralph T.C. (2005). Linear optical quantum computation with parity encoding. 2005 Quantum Electronics and Laser Science Conference (QELS), Baltimore, MD, May 22, 2005-May 27, 2005. Optical Society of America. doi: 10.1109/qels.2005.1548654

Linear optical quantum computation with parity encoding

2005

Journal Article

Measurement of quantum weak values of photon polarization

Pryde, G. J., O'Brien, J. L., White, A. G., Ralph, T. C. and Wiseman, H. M. (2005). Measurement of quantum weak values of photon polarization. Physical Review Letters, 94 (22) 220405, 220405-1-220405-4. doi: 10.1103/PhysRevLett.94.220405

Measurement of quantum weak values of photon polarization

2005

Journal Article

Quadrature-phase noise penalties of optically and electro-optically phase-locked lasers

Huntington, EH, Ralph, TC, Harb, CC and Schumaker, BL (2005). Quadrature-phase noise penalties of optically and electro-optically phase-locked lasers. Optics Communications, 250 (1-3), 178-190. doi: 10.1016/j.optcom.2005.02.023

Quadrature-phase noise penalties of optically and electro-optically phase-locked lasers

2005

Journal Article

Optimal photons for quantum-information processing

Rohde, Peter P., Ralph, Timothy C. and Nielsen, Michael A. (2005). Optimal photons for quantum-information processing. Physical Review A, 72 (5) 052332, 052332-1-052332-6. doi: 10.1103/PhysRevA.72.052332

Optimal photons for quantum-information processing

2005

Journal Article

Production of superpositions of coherent states in traveling optical fields with inefficient photon detection

Jeong, H., Lund, A. P. and Ralph, T. C. (2005). Production of superpositions of coherent states in traveling optical fields with inefficient photon detection. Physical Review A, 72 (1) 013801, 013801-1-013801-12. doi: 10.1103/PhysRevA.72.013801

Production of superpositions of coherent states in traveling optical fields with inefficient photon detection

2005

Journal Article

Continuous-variable quantum-state sharing via quantum disentanglement

Lance, A. M., Symul, T., Bowen, W. P., Sanders, B. C., Tyc, T., Ralph, T. C. and Lam, P. K. (2005). Continuous-variable quantum-state sharing via quantum disentanglement. Physical Review A, 71 (3) 033814, 1-11. doi: 10.1103/PhysRevA.71.033814

Continuous-variable quantum-state sharing via quantum disentanglement

2005

Journal Article

High-fidelity Z-measurement error encoding of optical qubits

O'Brien, J.L., Pryde, G.J., White, A.G. and Ralph, T.C. (2005). High-fidelity Z-measurement error encoding of optical qubits. Physical Review A, 71 (6) 060303, 060303-1-060303-4. doi: 10.1103/PhysRevA.71.060303

High-fidelity Z-measurement error encoding of optical qubits

2005

Journal Article

Frequency and temporal effects in linear optical quantum computing

Rohde, Peter P. and Ralph, Timothy C. (2005). Frequency and temporal effects in linear optical quantum computing. Physical Review A, 71 (3) 032320, 032320-1-032320-10. doi: 10.1103/PhysRevA.71.032320

Frequency and temporal effects in linear optical quantum computing

2005

Journal Article

Communicating continuous quantum variables between different Lorentz frames

Kok, P., Ralph, T. C. and Milburn, G. J. (2005). Communicating continuous quantum variables between different Lorentz frames. Quantum Information & Computation, 5 (3), 239-246.

Communicating continuous quantum variables between different Lorentz frames

2005

Journal Article

Demonstration of the spatial separation of the entangled quantum sidebands of an optical field

Huntington, E. H., Milford, G. N., Robilliard, C., Ralph, T. C., Glockl, O., Andersen, U. L., Lorenz, S. and Leuchs, G. (2005). Demonstration of the spatial separation of the entangled quantum sidebands of an optical field. Physical Review A, 71 (4) 041802, 041802-1-041802-4. doi: 10.1103/PhysRevA.71.041802

Demonstration of the spatial separation of the entangled quantum sidebands of an optical field

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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