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)

141 - 160 of 430 works

2013

Journal Article

Calculating unknown eigenvalues with a quantum algorithm

Zhou, Xiao-Qi, Kalasuwan, Pruet, Ralph, Timothy C. and O'Brien, Jeremy L. (2013). Calculating unknown eigenvalues with a quantum algorithm. Nature Photonics, 7 (3), 223-228. doi: 10.1038/NPHOTON.2012.360

Calculating unknown eigenvalues with a quantum algorithm

2013

Journal Article

Security of continuous-variable quantum cryptography with Gaussian postselection

Walk, Nathan, Ralph, Timothy C., Symul, Thomas and Lam, Ping Koy (2013). Security of continuous-variable quantum cryptography with Gaussian postselection. Physical Review A, 87 (2) 020303. doi: 10.1103/PhysRevA.87.020303

Security of continuous-variable quantum cryptography with Gaussian postselection

2013

Journal Article

Photonic boson sampling in a tunable circuit

Broome, Matthew A., Fedrizzi, Alessandro, Rahimi-Keshari, Saleh, Dove, Justin, Aaronson, Scott, Ralph, Timothy C. and White, Andrew G. (2013). Photonic boson sampling in a tunable circuit. Science, 339 (6121), 794-798. doi: 10.1126/science.1231440

Photonic boson sampling in a tunable circuit

2013

Journal Article

Open timelike curves violate Heisenberg's uncertainty principle

Pienaar, J. L., Ralph, T. C. and Myers, C. R. (2013). Open timelike curves violate Heisenberg's uncertainty principle. Physical Review Letters, 110 (6) 060501, 060501.1-060501.5. doi: 10.1103/PhysRevLett.110.060501

Open timelike curves violate Heisenberg's uncertainty principle

2013

Journal Article

Measurement-based method for verifying quantum discord

Rahimi-Keshari, Saleh, Caves, Carlton M. and Ralph, Timothy C. (2013). Measurement-based method for verifying quantum discord. Physical Review A, 87 (1) 012119, 012119.1-012119.5. doi: 10.1103/PhysRevA.87.012119

Measurement-based method for verifying quantum discord

2013

Conference Publication

Unconditional security of Gaussian post-selected continuous variable quantum key distribution

Walk, N., Symul, T., Lam, P. K. and Ralph, T. C. (2013). Unconditional security of Gaussian post-selected continuous variable quantum key distribution. 2013 Conference on Lasers and Electro-Optics Europe & International Quantum Electronics Conference (CLEO/Europe-IQEC 2013), Munich, 12-16 May 2013. Piscataway, NJ, United States: IEEE. doi: 10.1109/CLEOE-IQEC.2013.6801697

Unconditional security of Gaussian post-selected continuous variable quantum key distribution

2013

Conference Publication

Implementation of a quantum Fredkin gate using an entanglement resource

Ferreyrol, F., Ralph, T. C. and Pryde, G. J. (2013). Implementation of a quantum Fredkin gate using an entanglement resource. CLEO/EUROPE - IQEC 2013: Conference on Lasers and Electro-Optics - International Quantum Electronics Conference, Munich, Germany, 13-16 May, 2013. Piscataway, NJ, USA: IEEE. doi: 10.1109/CLEOE-IQEC.2013.6801703

Implementation of a quantum Fredkin gate using an entanglement resource

2013

Conference Publication

Building a quantum repeater with quantum memories and noiseless amplifiers

Lam, P. K., Hosseini, M., Campbell, G., Pinel, O., Sparkes, B., Twamley, J., Rebic, S., Chrzanowski, H. M., Assad, S., Bernu, J., Ralph, T. C., Walk, N., Symul, T. and Buchler, B. C. (2013). Building a quantum repeater with quantum memories and noiseless amplifiers. 10th Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2013, Kyoto, Japan, 30 June - 4 July 2013. Piscataway, NJ United States: I E E E. doi: 10.1109/CLEOPR.2013.6599943

Building a quantum repeater with quantum memories and noiseless amplifiers

2013

Conference Publication

Virtual noiseless amplification

Janousek, Jiri, Chrzanowski, Helen, Hosseini, Sarah, Assad, Syed, Symul, Thomas, Walk, Nathan, Ralph, Tim and Lam, Ping Koy (2013). Virtual noiseless amplification. CLEO/EUROPE - IQEC 2013: Conference on Lasers and Electro-Optics - International Quantum Electronics Conference, Munich, Germany, 13-16 May, 2013. Piscataway, NJ, USA: IEEE. doi: 10.1109/CLEOE-IQEC.2013.6801727

Virtual noiseless amplification

2013

Conference Publication

Experimental bosonsampling in a photonic circuit

Broome, Matthew A., Fedrizzi, Alessandro, Rahimi-Keshari, Saleh, Dove, Justin, Aaronson, Scott, Ralph, Timothy C. and White, Andrew G. (2013). Experimental bosonsampling in a photonic circuit. IEEE Photonics Society Summer Topical Meeting Series, PSSTMS 2013, Waikoloa, HI, United States, 8 - 10 July 2013. Piscataway, NJ, United States: IEEE. doi: 10.1109/PHOSST.2013.6614564

Experimental bosonsampling in a photonic circuit

2013

Journal Article

Quantum communication with an accelerated partner

Downes, T. G., Ralph, T. C. and Walk, N. (2013). Quantum communication with an accelerated partner. Physical Review A, 87 (1) 012327, 012327.1-012327.7. doi: 10.1103/PhysRevA.87.012327

Quantum communication with an accelerated partner

2013

Conference Publication

Direct characterization of any linear photonic device

Rahimi-Keshari, Saleh, Broome, Matthew A., Fickler, Robert, Fedrizzi, Alessandro, Ralph, Timothy C. and White, Andrew G. (2013). Direct characterization of any linear photonic device. Conference on Lasers and Electro-Optics Europe & International Quantum Electronics Conference (CLEO/Europe-IQEC), Munich, Germany, 12-16 May, 2013. Piscataway, NJ, USA: IEEE. doi: 10.1109/CLEOE-IQEC.2013.6801733

Direct characterization of any linear photonic device

2013

Conference Publication

Discord as a consumable resource

Gu, M., Chrzanowski, H. M., Assad, S. M., Symul, T., Modi, K., Ralph, T.C., Vedral, V. and Lam, P. K. (2013). Discord as a consumable resource. 10th Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2013, Kyoto, Japan, 30 June - 4 July 2013. Piscataway, NJ United States: I E E E. doi: 10.1109/CLEOPR.2013.6600227

Discord as a consumable resource

2013

Journal Article

Heralded noiseless amplification of a photon polarization qubit

Kocsis, S., Xiang, G. Y., Ralph, T. C. and Pryde, G. J. (2013). Heralded noiseless amplification of a photon polarization qubit. Nature Physics, 9 (1), 23-28. doi: 10.1038/NPHYS2469

Heralded noiseless amplification of a photon polarization qubit

2013

Conference Publication

Continuous-variable QKD with post-selection is secure

Ralph, T. C., Walk, N., Symul, T. and Lam, P. K. (2013). Continuous-variable QKD with post-selection is secure. IEEE Photonics Society Summer Topical Meeting Series, PSSTMS 2013, Waikoloa, HI, 8 - 10 July 2013. Piscataway, NJ United States: I E E E. doi: 10.1109/PHOSST.2013.6614521

Continuous-variable QKD with post-selection is secure

2013

Conference Publication

Experimental bosonsampling

Broome, M. A., Fedrizzi, A., Rahimi-Keshari, S., Dove, J., Aaronson, S., Ralph, T. C. and White, Andrew G. (2013). Experimental bosonsampling. CQO-X: The Tenth Rochester Conference on Coherence and Quantum Optics, 2013, with QIM 2: The Second International Conference on Quantum Information and Measurement, 2013, Rochester, NY, USA, 17-20 June, 2013. Washington, DC, USA: Optical Society of America. doi: 10.1364/QIM.2013.W5B.3

Experimental bosonsampling

2013

Conference Publication

Bosonsampling with realistic single-photon sources

Broome, Matthew A., Fedrizzi, Alessandro, Rahimi-Keshari, Saleh, Branczyk, Agata M., Dove, Justin, Aaronson, Scott, Ralph, Timothy C. and White, Andrew G. (2013). Bosonsampling with realistic single-photon sources. International Quantum Electronics Conference, IQEC 2013, Munich, Germany, 12 - 16 May 2013. Piscataway, NJ United States: I E E E. doi: 10.1109/CLEOE-IQEC.2013.6801699

Bosonsampling with realistic single-photon sources

2013

Conference Publication

Direct characterization of any linear photonic device

Fedrizzi, Alessandro, Broome, Matthew A., White, Andrew G., Fickler, Robert, Rahimi-Keshari, Saleh and Ralph, Timothy C. (2013). Direct characterization of any linear photonic device. APS March Meeting 2013, Baltimore, MD, USA, 18–22 March, 2013. College Park, MD, United States: American Physical Society.

Direct characterization of any linear photonic device

2013

Conference Publication

Experimental bosonsampling in a tunable optical network

Broome, Matthew A., Fedrizzi, Alessandro, Rahimi-Keshari, Saleh, Dove, Justin, Aaronson, Scott, Ralph, Timothy C. and White, Andrew G. (2013). Experimental bosonsampling in a tunable optical network. CLEO: QELS_Fundamental Science, CLEO:QELS FS 2013, San Jose, CA United States, 9 - 14 June 2013. San Jose, California United States: Quantum Simulators I (QW1C). doi: 10.1364/CLEO_QELS.2013.QW1C.3

Experimental bosonsampling in a tunable optical network

2012

Journal Article

General relativistic effects in quantum interference of photons

Zych, Magdalena, Costa, Fabio, Pikovski, Igor, Ralph, Timothy C. and Brukner, Caslav (2012). General relativistic effects in quantum interference of photons. Classical and Quantum Gravity, 29 (22) 224010, 224010-1-224010-18. doi: 10.1088/0264-9381/29/22/224010

General relativistic effects in quantum interference of photons

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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