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)

41 - 60 of 430 works

2020

Journal Article

Finite-size effects in continuous-variable quantum key distribution with Gaussian postselection

Hosseinidehaj, Nedasadat, Lance, Andrew M., Symul, Thomas, Walk, Nathan and Ralph, Timothy C. (2020). Finite-size effects in continuous-variable quantum key distribution with Gaussian postselection. Physical Review A, 101 (5) 052335, 052335. doi: 10.1103/physreva.101.052335

Finite-size effects in continuous-variable quantum key distribution with Gaussian postselection

2020

Journal Article

Continuous-variable quantum teleportation with vacuum-entangled Rindler modes

Foo, Joshua and Ralph, Timothy C. (2020). Continuous-variable quantum teleportation with vacuum-entangled Rindler modes. Physical Review D, 101 (8) 085006, 085006. doi: 10.1103/PhysRevD.101.085006

Continuous-variable quantum teleportation with vacuum-entangled Rindler modes

2020

Journal Article

Teleportation-based collective attacks in Gaussian quantum key distribution

Tserkis, Spyros, Hosseinidehaj, Nedasadat, Walk, Nathan and Ralph, Timothy C. (2020). Teleportation-based collective attacks in Gaussian quantum key distribution. Physical Review Research, 2 (1) 013208. doi: 10.1103/physrevresearch.2.013208

Teleportation-based collective attacks in Gaussian quantum key distribution

2019

Journal Article

Fundamental building block for all-optical scalable quantum networks

Lee, Seung-Woo, Ralph, Timothy C. and Jeong, Hyunseok (2019). Fundamental building block for all-optical scalable quantum networks. Physical Review A, 100 (5) 052303. doi: 10.1103/PhysRevA.100.052303

Fundamental building block for all-optical scalable quantum networks

2019

Journal Article

Passive, broadband, and low-frequency suppression of laser amplitude noise to the shot-noise limit using a hollow-core fiber

Allen, Euan J., Ferranti, Giacomo, Rusimova, Kristina R., Francis-Jones, Robert J. A., Azini, Maria, Mahler, Dylan H., Ralph, Timothy C., Mosley, Peter J. and Matthews, Jonathan C. F. (2019). Passive, broadband, and low-frequency suppression of laser amplitude noise to the shot-noise limit using a hollow-core fiber. Physical Review Applied, 12 (4) 044073. doi: 10.1103/PhysRevApplied.12.044073

Passive, broadband, and low-frequency suppression of laser amplitude noise to the shot-noise limit using a hollow-core fiber

2019

Journal Article

Satellite testing of a gravitationally induced quantum decoherence model

Xu, Ping, Ma, Yiqiu, Ren, Ji-Gang, Yong, Hai-Lin, Ralph, Timothy C., Liao, Sheng-Kai, Yin, Juan, Liu, Wei-Yue, Cai, Wen-Qi, Han, Xuan, Wu, Hui-Nan, Wang, Wei-Yang, Li, Feng-Zhi, Yang, Meng, Lin, Feng-Li, Li, Li, Liu, Nai-Le, Chen, Yu-Ao, Lu, Chao-Yang, Chen, Yanbei, Fan, Jingyun, Peng, Cheng-Zhi and Pan, Jian-Wei (2019). Satellite testing of a gravitationally induced quantum decoherence model. Science, 366 (6461), 132-135. doi: 10.1126/science.aay5820

Satellite testing of a gravitationally induced quantum decoherence model

2019

Journal Article

Tight bounds for private communication over bosonic Gaussian channels based on teleportation simulation with optimal finite resources

Laurenza, Riccardo, Tserkis, Spyros, Banchi, Leonardo, Braunstein, Samuel L., Ralph, Timothy C. and Pirandola, Stefano (2019). Tight bounds for private communication over bosonic Gaussian channels based on teleportation simulation with optimal finite resources. Physical Review A, 100 (4) 042301. doi: 10.1103/PhysRevA.100.042301

Tight bounds for private communication over bosonic Gaussian channels based on teleportation simulation with optimal finite resources

2019

Journal Article

Reversible time travel with freedom of choice

Baumeler, Ämin, Costa, Fabio, Ralph, Timothy C., Wolf, Stefan and Zych, Magdalena Anna (2019). Reversible time travel with freedom of choice. Classical and Quantum Gravity, 36 (22) 224002, 224002. doi: 10.1088/1361-6382/ab4973

Reversible time travel with freedom of choice

2019

Journal Article

Quantum metrology in the Kerr metric

Kish, S. P. and Ralph, T. C. (2019). Quantum metrology in the Kerr metric. Physical Review D, 99 (12) 124015. doi: 10.1103/PhysRevD.99.124015

Quantum metrology in the Kerr metric

2019

Journal Article

Universal transformation of displacement operators and its application to homodyne tomography in differing relativistic reference frames

Onoe, Sho and Ralph, Timothy C. (2019). Universal transformation of displacement operators and its application to homodyne tomography in differing relativistic reference frames. Physical Review D, 99 (11) 116001. doi: 10.1103/PhysRevD.99.116001

Universal transformation of displacement operators and its application to homodyne tomography in differing relativistic reference frames

2019

Conference Publication

Maximisation of quantum correlations under local filtering operations

Wollmann, Sabine, Ducuara, Andrés F., Qiang, Xiaogang, Tasker, Joel F., Zhou, Xiaoqi, Wang, Jianwei, Wilkes, Callum M., Loke, Thomas, Oagara, Sean, Kling, Laurent, Marshall, Graham D., Santagati, Raffaele, Ralph, Timothy C., Wang, Jingbo B., Oabrien, Jeremy L., Thompson, Mark G., Skrzypczyk, Paul and Matthews, Jonathan C. F. (2019). Maximisation of quantum correlations under local filtering operations. 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), Munich, Germany, 23 - 27 June 2019. Piscataway, NJ, United States: Institute of Electrical and Electronics Engineers. doi: 10.1109/CLEOE-EQEC.2019.8871647

Maximisation of quantum correlations under local filtering operations

2019

Journal Article

Optimal realistic attacks in continuous-variable quantum key distribution

Hosseinidehaj, Nedasadat, Walk, Nathan and Ralph, Timothy C. (2019). Optimal realistic attacks in continuous-variable quantum key distribution. Physical Review A, 99 (5) 052336. doi: 10.1103/PhysRevA.99.052336

Optimal realistic attacks in continuous-variable quantum key distribution

2019

Journal Article

Quantifying entanglement of formation for two-mode Gaussian states: analytical expressions for upper and lower bounds and numerical estimation of its exact value

Tserkis, Spyros, Onoe, Sho and Ralph, Timothy C. (2019). Quantifying entanglement of formation for two-mode Gaussian states: analytical expressions for upper and lower bounds and numerical estimation of its exact value. Physical Review A, 99 (5) 052337. doi: 10.1103/PhysRevA.99.052337

Quantifying entanglement of formation for two-mode Gaussian states: analytical expressions for upper and lower bounds and numerical estimation of its exact value

2019

Journal Article

Quantum correlations and global coherence in distributed quantum computing

Shahandeh, Farid, Lund, Austin P. and Ralph, Timothy C. (2019). Quantum correlations and global coherence in distributed quantum computing. Physical Review A, 99 (5) 052303. doi: 10.1103/PhysRevA.99.052303

Quantum correlations and global coherence in distributed quantum computing

2019

Journal Article

Correlations detected in a quantum vacuum

Moskalenko, Andrey S. and Ralph, Timothy C. (2019). Correlations detected in a quantum vacuum. Nature, 568 (7751), 178-179. doi: 10.1038/d41586-019-01083-z

Correlations detected in a quantum vacuum

2019

Journal Article

Entanglement properties of a measurement-based entanglement distillation experiment

Jeng, Hao, Tserkis, Spyros, Haw, Jing Yan, Chrzanowski, Helen M., Janousek, Jiri, Ralph, Timothy C., Lam, Ping Koy and Assad, Syed M. (2019). Entanglement properties of a measurement-based entanglement distillation experiment. Physical Review A, 99 (4) 042304. doi: 10.1103/PhysRevA.99.042304

Entanglement properties of a measurement-based entanglement distillation experiment

2019

Journal Article

Estimation of gravitational acceleration with quantum optical interferometers

Chen, S. Y. and Ralph, T. C. (2019). Estimation of gravitational acceleration with quantum optical interferometers. Physical Review A, 99 (2) 023803. doi: 10.1103/PhysRevA.99.023803

Estimation of gravitational acceleration with quantum optical interferometers

2019

Journal Article

Decoherence of the radiation from an accelerated quantum source

Su, Daiqin and Ralph, Timothy C. (2019). Decoherence of the radiation from an accelerated quantum source. Physical Review X, 9 (1) 011007. doi: 10.1103/PhysRevX.9.011007

Decoherence of the radiation from an accelerated quantum source

2019

Book

A Guide to Experiments in Quantum Optics

Bachor, Hans and Ralph, Timothy (2019). A Guide to Experiments in Quantum Optics. Weinheim, Germany: Wiley-VCH. doi: 10.1002/9783527695805

A Guide to Experiments in Quantum Optics

2019

Conference Publication

Quantum algorithms on a four-qubit photonic controlled-shift gate

Ho, Joseph, Patel, Raj B., Ralph, Timothy C. and Pryde, Geoff J. (2019). Quantum algorithms on a four-qubit photonic controlled-shift gate. Quantum Information and Measurement 2019, Rome, Italy , 4–6 April 2019. Washington, D.C.: OSA - The Optical Society. doi: 10.1364/QIM.2019.F5A.41

Quantum algorithms on a four-qubit photonic controlled-shift gate

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

    Beyond quantum field theory on a curved background

    Principal Advisor

  • Master Philosophy

    Resolving paradoxes of closed timelike curves

    Principal Advisor

  • Doctor Philosophy

    Quantum information processing with linear optics

    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

    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

  • 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

Need help?

For help with finding experts, story ideas and media enquiries, contact our Media team:

communications@uq.edu.au