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)

61 - 80 of 429 works

2018

Journal Article

Generation of a cat state in an optical sideband

Serikawa, Takahiro, Yoshikawa, Jun-Ichi, Takeda, Shuntaro, Yonezawa, Hidehiro, Ralph, Timothy C., Huntington, Elanor H. and Furusawa, Akira (2018). Generation of a cat state in an optical sideband. Physical Review Letters, 121 (14) 143602, 143602. doi: 10.1103/PhysRevLett.121.143602

Generation of a cat state in an optical sideband

2018

Journal Article

Can the fluctuations of the quantum vacuum solve the cosmological constant problem?

Cree, Samuel S., Davis, Tamara M., Ralph, Timothy C., Wang, Qingdi, Zhu, Zhen and Unruh, William G. (2018). Can the fluctuations of the quantum vacuum solve the cosmological constant problem?. Physical Review D, 98 (6) 063506. doi: 10.1103/PhysRevD.98.063506

Can the fluctuations of the quantum vacuum solve the cosmological constant problem?

2018

Journal Article

Large-scale silicon quantum photonics implementing arbitrary two-qubit processing

Qiang, Xiaogang, Zhou, Xiaoqi, Wang, Jianwei, Wilkes, Callum M., Loke, Thomas, O'Gara, Sean, Kling, Laurent, Marshall, Graham D., Santagati, Raffaele, Ralph, Timothy C., Wang, Jingbo B., O'Brien, Jeremy L., Thompson, Mark G. and Matthews, Jonathan C. F. (2018). Large-scale silicon quantum photonics implementing arbitrary two-qubit processing. Nature Photonics, 12 (9), 534-539. doi: 10.1038/s41566-018-0236-y

Large-scale silicon quantum photonics implementing arbitrary two-qubit processing

2018

Journal Article

Particle production and apparent decoherence due to an accelerated time delay

Onoe, Sho, Su, Daiqin and Ralph, Timothy. C. (2018). Particle production and apparent decoherence due to an accelerated time delay. Physical Review D, 98 (3) 036011. doi: 10.1103/PhysRevD.98.036011

Particle production and apparent decoherence due to an accelerated time delay

2018

Journal Article

Space QUEST mission proposal: experimentally testing decoherence due to gravity

Joshi, Siddarth Koduru, Pienaar, Jacques, Ralph, Timothy C., Cacciapuoti, Luigi, McCutcheon, Will, Rarity, John, Giggenbach, Dirk, Lim, Jin Gyu, Makarov, Vadim, Fuentes, Ivette, Scheidl, Thomas, Beckert, Erik, Bourennane, Mohamed, Bruschi, David Edward, Cabello, Adam, Capmany, Jose, Carrasco-Casado, Alberto, Diamanti, Eleni, Dusek, Miloslav, Elser, Dominique, Gulinatti, Angelo, Hadfield, Robert H., Jennewein, Thomas, Kaltenbaek, Rainer, Krainak, Michael A., Lo, Hoi-Kwong, Marquardt, Christoph, Milburn, Gerard, Peev, Momtchil ... Ursin, Rupert (2018). Space QUEST mission proposal: experimentally testing decoherence due to gravity. New Journal of Physics, 20 (6) 063016, 063016. doi: 10.1088/1367-2630/aac58b

Space QUEST mission proposal: experimentally testing decoherence due to gravity

2018

Journal Article

Quantum error correction of continuous-variable states with realistic resources

Dias, Josephine and Ralph, T. C. (2018). Quantum error correction of continuous-variable states with realistic resources. Physical Review A, 97 (3) 032335. doi: 10.1103/PhysRevA.97.032335

Quantum error correction of continuous-variable states with realistic resources

2018

Journal Article

Passive quantum error correction of linear optics networks through error averaging

Marshman, Ryan J., Lund, Austin P., Rohde, Peter P. and Ralph, Timothy C. (2018). Passive quantum error correction of linear optics networks through error averaging. Physical Review A, 97 (2) 022324, 1-15. doi: 10.1103/PhysRevA.97.022324

Passive quantum error correction of linear optics networks through error averaging

2018

Journal Article

Violation of Bell's inequality using continuous variable measurements

Thearle, Oliver, Janousek, Jiri, Armstrong, Seiji, Hosseini, Sara, Schünemann, Melanie, Assad, Syed, Symul, Thomas, James, Matthew R., Huntington, Elanor, Ralph, Timothy C. and Lam, Ping Koy (2018). Violation of Bell's inequality using continuous variable measurements. Physical Review Letters, 120 (4) 040406, 040406. doi: 10.1103/PhysRevLett.120.040406

Violation of Bell's inequality using continuous variable measurements

2018

Conference Publication

Generation of Schrödinger’s cat state in an optical double sideband mode

Serikawa, Takahiro, Yoshikawa, Jun-ichi, Yonezawa, Hidehiro, Ralph, Timothy C., Huntington, Elanor H. and Furusawa, Akira (2018). Generation of Schrödinger’s cat state in an optical double sideband mode. CLEO: QELS_Fundamental Science, CLEO_QELS 2018, San Jose, CA, United States, 13–18 May 2018. Washington D.C., United States: OSA - The Optical Society. doi: 10.1364/CLEO_QELS.2018.FTh4G.6

Generation of Schrödinger’s cat state in an optical double sideband mode

2018

Conference Publication

The quest for nonclassicality using number-resolving single-photon detectors

Abrahão, Raphael A., Shahandeh, Farid, Gillett, Geoff, Ringbauer, Martin, Weinhold, Till, Almeida, Marcelo P., Ralph, Timothy C. and White, Andrew G. (2018). The quest for nonclassicality using number-resolving single-photon detectors. Frontiers in Optics, FIO 2018, Washington, DC USA, 18-20 September 2018. Washington, D.C.: OSA - The Optical Society. doi: 10.1364/FIO.2018.JTu2A.55

The quest for nonclassicality using number-resolving single-photon detectors

2017

Journal Article

Quantifying entanglement in two-mode Gaussian states

Tserkis, Spyros and Ralph, Timothy C. (2017). Quantifying entanglement in two-mode Gaussian states. Physical Review A, 96 (6) 062338, 1-6. doi: 10.1103/PhysRevA.96.062338

Quantifying entanglement in two-mode Gaussian states

2017

Journal Article

Erratum: Ultrafine entanglement witnessing

Shahandeh, Farid, Ringbauer, Martin, Loredo, Juan C. and Ralph, Timothy C. (2017). Erratum: Ultrafine entanglement witnessing. Physical Review Letters, 119 (26) 269901. doi: 10.1103/physrevlett.119.269901

Erratum: Ultrafine entanglement witnessing

2017

Journal Article

Quantum enhancement of signal-to-noise ratio with a heralded linear amplifier

Zhao, Jie, Dias, Josephine, Haw, Jing Yan, Symul, Thomas, Bradshaw, Mark, Blandino, Remi, Ralph, Timothy, Assad, Syed M. and Lam, Ping Koy (2017). Quantum enhancement of signal-to-noise ratio with a heralded linear amplifier. Optica, 4 (11), 1421-1428. doi: 10.1364/OPTICA.4.001421

Quantum enhancement of signal-to-noise ratio with a heralded linear amplifier

2017

Journal Article

Quantum-limited measurement of space-time curvature with scaling beyond the conventional Heisenberg limit

Kish, S. P. and Ralph, T. C. (2017). Quantum-limited measurement of space-time curvature with scaling beyond the conventional Heisenberg limit. Physical Review A, 96 (4) 041801. doi: 10.1103/PhysRevA.96.041801

Quantum-limited measurement of space-time curvature with scaling beyond the conventional Heisenberg limit

2017

Journal Article

Black hole squeezers

Su, Daiqin, Ho, C. T. Marco, Mann, Robert B. and Ralph, Timothy C. (2017). Black hole squeezers. Physical Review D, 96 (6) 065017. doi: 10.1103/PhysRevD.96.065017

Black hole squeezers

2017

Journal Article

Quantum correlations in nonlocal boson sampling

Shahandeh, Farid, Lund, Austin P. and Ralph, Timothy C. (2017). Quantum correlations in nonlocal boson sampling. Physical Review Letters, 119 (12) 120502, 120502. doi: 10.1103/PhysRevLett.119.120502

Quantum correlations in nonlocal boson sampling

2017

Journal Article

Exact boson sampling using Gaussian continuous-variable measurements

Lund, A. P., Rahimi-Keshari, S. and Ralph, T. C. (2017). Exact boson sampling using Gaussian continuous-variable measurements. Physical Review A, 96 (2) 022301. doi: 10.1103/PhysRevA.96.022301

Exact boson sampling using Gaussian continuous-variable measurements

2017

Journal Article

Quantum circuit model for non-inertial objects: a uniformly accelerated mirror

Su, Daiqin, Ho, C. T. Marco, Mann, Robert B. and Ralph, Timothy C. (2017). Quantum circuit model for non-inertial objects: a uniformly accelerated mirror. New Journal of Physics, 19 (6) 063017, 063017. doi: 10.1088/1367-2630/aa71d1

Quantum circuit model for non-inertial objects: a uniformly accelerated mirror

2017

Journal Article

Experimental test of photonic entanglement in accelerated reference frames

Fink, Matthias, Rodriguez-Aramendia, Ana, Handsteiner, Johannes, Ziarkash, Abdul, Steinlechner, Fabian, Scheidl, Thomas, Fuentes, Ivette, Pienaar, Jacques, Ralph, Timothy C. and Ursin, Rupert (2017). Experimental test of photonic entanglement in accelerated reference frames. Nature Communications, 8 (1) 15304, 15304. doi: 10.1038/ncomms15304

Experimental test of photonic entanglement in accelerated reference frames

2017

Journal Article

Quantum sampling problems, BosonSampling and quantum supremacy

Lund, A. P., Bremner, Michael J. and Ralph, T. C. (2017). Quantum sampling problems, BosonSampling and quantum supremacy. NPJ Quantum Information, 3 (1) 0018. doi: 10.1038/s41534-017-0018-2

Quantum sampling problems, BosonSampling and quantum supremacy

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

    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