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)

301 - 320 of 430 works

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

2004

Journal Article

Utilizing encoding in scalable linear optics quantum computing

Hayes, A. J. F., Gilchrist, A., Myers, C. R. and Ralph, T. C. (2004). Utilizing encoding in scalable linear optics quantum computing. Journal of Optics B-quantum And Semiclassical Optics, 6 (12), 533-541. doi: 10.1088/1464-4266/6/12/008

Utilizing encoding in scalable linear optics quantum computing

2004

Journal Article

Measuring a photonic qubit without destroying it

Pryde, G.J., O'Brien, J.L., White, A.G., Bartlett, S.D. and Ralph, T.C. (2004). Measuring a photonic qubit without destroying it. Physical Review Letters, 92 (19) 193002, 190402-1-190402-4. doi: 10.1103/PhysRevLett.92.190402

Measuring a photonic qubit without destroying it

2004

Journal Article

Components of optical qubits encoded in sideband modes

Huntington, E. H. and Ralph, T. C. (2004). Components of optical qubits encoded in sideband modes. Physical Review A, 69 (4) 042318, 042318-1-042318-5. doi: 10.1103/PhysRevA.69.042318

Components of optical qubits encoded in sideband modes

2004

Journal Article

Transmission of optical coherent-state qubits

Glancy, S., Vasconcelos, H. M. and Ralph, T. C. (2004). Transmission of optical coherent-state qubits. Physical Review A, 70 (2) 022317, 022317-1-022317-7. doi: 10.1103/PhysRevA.70.022317

Transmission of optical coherent-state qubits

2004

Book

A Guide to Experiments in quantum optics

Bachor, H. A. and Ralph, T. C. (2004). A Guide to Experiments in quantum optics. 2nd ed. Weinheim: Wiley-VCH.

A Guide to Experiments in quantum optics

2004

Journal Article

Experimental characterization of continuous-variable entanglement

Bowen, W. P., Schnabel, R., Lam, P. K. and Ralph, T. C. (2004). Experimental characterization of continuous-variable entanglement. Physical Review A - Atomic, Molecular, and Optical Physics, 69 (1). doi: 10.1103/PhysRevA.69.012304

Experimental characterization of continuous-variable entanglement

2004

Journal Article

Quantum process tomography of a controlled-NOT gate

O'Brien, Jeremy L., Pryde, Geoff, Gilchrist, Alexei, James, Dan, Langford, Nathan, Ralph, T. C. and White, A. G. (2004). Quantum process tomography of a controlled-NOT gate. Physical Review Letters, 93 (8) 080502, 080502-1-080502-4. doi: 10.1103/PhysRevLett.93.080502

Quantum process tomography of a controlled-NOT gate

2004

Journal Article

Optimal cloning for finite distributions of coherent states

Cochrane, P. T., Ralph, T. C. and Dolinska, A. (2004). Optimal cloning for finite distributions of coherent states. Physical Review A, 69 (4) 042313, 042313-1-042313-6. doi: 10.1103/PhysRevA.69.042313

Optimal cloning for finite distributions of coherent states

2004

Other Outputs

Quantum Process Tomography of a Controlled-NOT Gate

O'Brien, J. L., Pryde, G. J., Gilchrist, A., James, D. F. V., Langford, N. K., Ralph, T. C. and White, A. G. (2004). Quantum Process Tomography of a Controlled-NOT Gate.

Quantum Process Tomography of a Controlled-NOT Gate

2004

Journal Article

Conditional production of superpositions of coherent states with inefficient photon detection

Lund, A. P., Jeong, H., Ralph, T. C. and Kim, M. S. (2004). Conditional production of superpositions of coherent states with inefficient photon detection. Physical Review A, 70 (2) 020101, 020101-1-020101-4. doi: 10.1103/PhysRevA.70.020101

Conditional production of superpositions of coherent states with inefficient photon detection

2004

Conference Publication

Photon number diagram for characterizing continuous variable entanglement. , pp. 315-323

Bowen, W. P., Hsu, M. T. L., Symul, T., Lance, A. M., Buchler, B. C., Schnabel, R., Treps, N., Bachor, H.-A., Ralph, T. C. and Lam, P. K. (2004). Photon number diagram for characterizing continuous variable entanglement. , pp. 315-323. Laser Spectroscopy, Palm Cove, Queensland Australia, 14th -18th July, 2003. SINGAPORE: WORLD SCIENTIFIC PUBL CO PTE LTD. doi: 10.1142/9789812703002_0048

Photon number diagram for characterizing continuous variable entanglement. , pp. 315-323

2004

Journal Article

Quantum cryptography without switching

Weedbrook, C., Lance, A. M., Bowen, W. P., Symul, T., Ralph, T. C. and Lam, P. K. (2004). Quantum cryptography without switching. Physical Review Letters, 93 (17) 170504, 1-4. doi: 10.1103/PhysRevLett.93.170504

Quantum cryptography without switching

2004

Journal Article

Deterministic generation of tailored-optical-coherent-state superpositions

Ritsch, H., Milburn, G. J. and Ralph, T. C. (2004). Deterministic generation of tailored-optical-coherent-state superpositions. Physical Review A, 70 (3) 033804, 033804-1-033804-4. doi: 10.1103/PhysRevA.70.033804

Deterministic generation of tailored-optical-coherent-state superpositions

2004

Conference Publication

Investigation of two qubit quantum gates in linear optics

Ralph, T. C., Langford, N. K., Bell, T. B., O'Brien, J. L., Pryde, G. J., White, A. G. and Milburn, G. J. (2004). Investigation of two qubit quantum gates in linear optics. Quantum Communications and Quantum Imaging, San Diego, USA, 6-8 August 2003. Bellingham, WA, U.S.A.: SPIE. doi: 10.1117/12.505078

Investigation of two qubit quantum gates in linear optics

2004

Book Chapter

Squeezing from lasers

Ralph, T. C. (2004). Squeezing from lasers. Quantum Squeezing. (pp. 141-170) edited by P D Drummond and Z Ficek. Berlin: Springer.

Squeezing from lasers

2004

Journal Article

Scaling of multiple postselected quantum gates in optics

Ralph, T. C. (2004). Scaling of multiple postselected quantum gates in optics. Physical Review A, 70 (1) 012312, 012312-1-012312-5. doi: 10.1103/PhysRevA.70.012312

Scaling of multiple postselected quantum gates in optics

2004

Journal Article

Generation of macroscopic superposition states with small nonlinearity

Jeong, H., Kim, M. S., Ralph, T. C. and Ham, B. S. (2004). Generation of macroscopic superposition states with small nonlinearity. Physical Review A, 70 (6) 061801, 061801-1-061801-4. doi: 10.1103/PhysRevA.70.061801

Generation of macroscopic superposition states with small nonlinearity

2004

Journal Article

Schrodinger cats and their power for quantum information processing

Gilchrist, A., Nemoto, K., Munro, W. J., Ralph, T. C., Glancy, S., Braunstein, S. L. and Milburn, G. J. (2004). Schrodinger cats and their power for quantum information processing. Journal of Optics B- Quantum and Semiclassical Optics, 6 (8), S828-S833. doi: 10.1088/1464-4266/6/8/032

Schrodinger cats and their power for quantum information processing

2004

Journal Article

Experimental characterization of continuous-variable entanglement

Bowen, W. P., Schnabel, R., Lam, P. K. and Ralph, T. C. (2004). Experimental characterization of continuous-variable entanglement. Physical Review A, 69 (1) 012304, 1-17. doi: 10.1103/PhysRevA.69.012304

Experimental characterization of continuous-variable entanglement

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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