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

435 works between 1991 and 2025
All (435) Journal Article (330) Book Chapter (7) Conference Publication (88) Book (2) Other Outputs (8)

281 - 300 of 435 works

2006

Conference Publication

Homodyne measurement of average photon number

Webb, J. G., Ralph, T. C. and Huntington, E. H. (2006). Homodyne measurement of average photon number. Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference, CLEO/QELS 2006, , , May 21, 2006-May 26, 2006. Optical Society of America. doi: 10.1109/CLEO.2006.4628675

Homodyne measurement of average photon number

2006

Journal Article

Quantum-state engineering with continuous-variable postselection

Lance, Andrew M., Jeong, Hyunseok, Grosse, Nicolai B., Symul, Thomas, Ralph, Timothy C. and Lam, Ping Koy (2006). Quantum-state engineering with continuous-variable postselection. Physical Review A, 73 (4) 041801, 041801-1-041801-4. doi: 10.1103/PhysRevA.73.041801

Quantum-state engineering with continuous-variable postselection

2006

Journal Article

Conditional quantum-state engineering using ancillary squeezed-vacuum states

Jeong, Hyunseok, Lance, Andrew M., Grosse, Nicolai B., Symul, Thomas, Lam, Ping Koy and Ralph, Timothy C. (2006). Conditional quantum-state engineering using ancillary squeezed-vacuum states. Physical Review A, 74 (3) 033813, 033813-1-033813-10. doi: 10.1103/PhysRevA.74.033813

Conditional quantum-state engineering using ancillary squeezed-vacuum states

2005

Conference Publication

Successful quantum key distribution with simultaneous quadrature measurement in the presence of 90% line loss

Symul, T., Lance, A. M., Sharma, V., Lam, P. K., Weedbrook, C. and Ralph, T. C. (2005). Successful quantum key distribution with simultaneous quadrature measurement in the presence of 90% line loss. doi: 10.1109/EQEC.2005.1567468

Successful quantum key distribution with simultaneous quadrature measurement in the presence of 90% line loss

2005

Conference Publication

Using entanglement in photonic qubit measurements

Pryde, G. J., O'Brien, J. L., White, A. G., Ralph, T. C., Bartlett, S. D. and Wiseman, H. M. (2005). Using entanglement in photonic qubit measurements. Optics and photonics 2005: Quantum Communications and Quantum Imaging III, San Diego, CA, United States, 31 July - 4 August 2005. Bellingham, WA, United States: S P I E - International Society for Optical Engineering. doi: 10.1117/12.616166

Using entanglement in photonic qubit measurements

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

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

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

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

2005

Journal Article

Adaptive phase measurements in linear optical quantum computation

Ralph, T. C., Lund, A. P. and Wiseman, H. M. (2005). Adaptive phase measurements in linear optical quantum computation. Journal of Optics B-quantum And Semiclassical Optics, 7 (10), S245-S249. doi: 10.1088/1464-4266/7/10/007

Adaptive phase measurements in linear optical quantum computation

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

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.

Supervision history

Current supervision

  • 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

    Quantum information processing with linear optics

    Principal Advisor

  • Master Philosophy

    Resolving paradoxes of closed timelike curves

    Principal Advisor

  • Doctor Philosophy

    Thermodynamic fluctuation relations for gravitating quantum systems

    Associate Advisor

    Other advisors: Dr Carolyn Wood

  • Doctor Philosophy

    Demonstration of relativistic Bohmian trajectories of photons

    Associate Advisor

    Other advisors: Associate Professor Jacqui Romero

  • 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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