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)

101 - 120 of 429 works

2016

Conference Publication

Enhancing optical quantum channels

Lund, Austin and Ralph, Timothy C. (2016). Enhancing optical quantum channels. SPIE, San Diego, CA, United States, 28–29 August 2016. Bellingham, WA, United States: SPIE. doi: 10.1117/12.2237438

Enhancing optical quantum channels

2015

Journal Article

Replicating the benefits of Deutschian closed timelike curves without breaking causality

Yuan, Xiao, Assad, Syed M., Thompson, Jayne, Haw, Jing Yan, Vedral, Vlatko, Ralph, Timothy C., Lam, Ping Koy, Weedbrook, Christian and Gu, Mile (2015). Replicating the benefits of Deutschian closed timelike curves without breaking causality. npj Quantum Information, 1 (1) 15007. doi: 10.1038/npjqi.2015.7

Replicating the benefits of Deutschian closed timelike curves without breaking causality

2015

Journal Article

Nearly deterministic Bell measurement with multiphoton entanglement for efficient quantum-information processing

Lee, Seung-Woo, Park, Kimin, Ralph, Timothy C. and Jeong, Hyunseok (2015). Nearly deterministic Bell measurement with multiphoton entanglement for efficient quantum-information processing. Physical Review A, 92 (5) 052324. doi: 10.1103/PhysRevA.92.052324

Nearly deterministic Bell measurement with multiphoton entanglement for efficient quantum-information processing

2015

Journal Article

Undoing the effect of loss on quantum entanglement

Ulanov, Alexander E., Fedorov, Ilya A., Pushkina, Anastasia A., Kurochkin, Yury V., Ralph, Timothy C. and Lvovsky A.I. (2015). Undoing the effect of loss on quantum entanglement. Nature Photonics, 9 (11), 764-768. doi: 10.1038/nphoton.2015.195

Undoing the effect of loss on quantum entanglement

2015

Journal Article

Properties of hybrid entanglement between discrete- and continuous-variable states of light

Costanzo, L. S., Zavatta, A., Grandi, S., Bellini, M., Jeong, H., Kang, M., Lee, S.-W. and Ralph, T. C. (2015). Properties of hybrid entanglement between discrete- and continuous-variable states of light. Physica Scripta, 90 (7) 074045, 1-7. doi: 10.1088/0031-8949/90/7/074045

Properties of hybrid entanglement between discrete- and continuous-variable states of light

2015

Journal Article

Operational discord measure for Gaussian states with Gaussian measurements

Rahimi-Keshari, Saleh, Ralph, Timothy C. and Caves, Carlton M. (2015). Operational discord measure for Gaussian states with Gaussian measurements. New Journal of Physics, 17 (6) 063037, 1-12. doi: 10.1088/1367-2630/17/6/063037

Operational discord measure for Gaussian states with Gaussian measurements

2015

Journal Article

Quantum key distribution without sending a quantum signal

Ralph, T. C. and Walk, N. (2015). Quantum key distribution without sending a quantum signal. New Journal of Physics, 17 (6) 063008, 1-13. doi: 10.1088/1367-2630/17/6/063008

Quantum key distribution without sending a quantum signal

2015

Journal Article

Photon sorting, efficient bell measurements, and a deterministic controlled- Z gate using a passive two-level nonlinearity

Ralph, T. C., Sollner, I., Mahmoodian, S., White, A. G. and Lodahl, P. (2015). Photon sorting, efficient bell measurements, and a deterministic controlled- Z gate using a passive two-level nonlinearity. Physical Review Letters, 114 (17) 173603, 173603-1-173603-5. doi: 10.1103/PhysRevLett.114.173603

Photon sorting, efficient bell measurements, and a deterministic controlled- Z gate using a passive two-level nonlinearity

2015

Journal Article

Nearly deterministic bell measurement for multiphoton qubits and its application to quantum information processing

Lee, Seung-Woo, Park, Kimin, Ralph, Timothty C and Jeong, Hyunseok (2015). Nearly deterministic bell measurement for multiphoton qubits and its application to quantum information processing. Physical Review Letters, 114 (11) 113603, 113603. doi: 10.1103/PhysRevLett.114.113603

Nearly deterministic bell measurement for multiphoton qubits and its application to quantum information processing

2015

Journal Article

What can quantum optics say about computational complexity theory?

Rahimi-Keshari, Saleh, Lund, Austin P and Ralph, Timothy C (2015). What can quantum optics say about computational complexity theory?. Physical Review Letters, 114 (6) 060501, 060501. doi: 10.1103/PhysRevLett.114.060501

What can quantum optics say about computational complexity theory?

2014

Journal Article

Detecting the degree of macroscopic quantumness using an overlap measurement

Jeong, Hyunseok, Noh, Changsuk, Bae, Seunglee, Angelakis, Dimitris G. and Ralph, Timothy C. (2014). Detecting the degree of macroscopic quantumness using an overlap measurement. Journal of the Optical Society of America B: Optical Physics, 31 (12), 3057-3066. doi: 10.1364/JOSAB.31.003057

Detecting the degree of macroscopic quantumness using an overlap measurement

2014

Journal Article

Quantum estimation of the Schwarzschild spacetime parameters of the Earth

Bruschi, David Edward, Datta, Animesh, Ursin, Rupert, Ralph, Timothy C. and Fuentes, Ivette (2014). Quantum estimation of the Schwarzschild spacetime parameters of the Earth. Physical Review D - Particles, Fields, Gravitation and Cosmology, 90 (12) 124001, 124001-1-124001-10. doi: 10.1103/PhysRevD.90.124001

Quantum estimation of the Schwarzschild spacetime parameters of the Earth

2014

Journal Article

Theoretical analysis of an ideal noiseless linear amplifier for Einstein-Podolsky-Rosen entanglement distillation

Bernu, J., Armstrong, S., Symul, T., Ralph, T. C. and Lam, P. K. (2014). Theoretical analysis of an ideal noiseless linear amplifier for Einstein-Podolsky-Rosen entanglement distillation. Journal of Physics B: Atomic, Molecular and Optical Physics, 47 (21) 215503, 1-10. doi: 10.1088/0953-4075/47/21/215503

Theoretical analysis of an ideal noiseless linear amplifier for Einstein-Podolsky-Rosen entanglement distillation

2014

Journal Article

Experimental hybrid entanglement between quantum and classical states of light

Costanzo, Luca S., Zavatta, Alessandro, Grandi, Samuele, Bellini, Marco, Jeong, Hyunseok, Kang, Minsu, Lee, Seung-Woo and Ralph, Timothy C. (2014). Experimental hybrid entanglement between quantum and classical states of light. International Journal of Quantum Information, 12 (7-8), 1560015-1-1560015-11. doi: 10.1142/S0219749915600151

Experimental hybrid entanglement between quantum and classical states of light

2014

Journal Article

Quantum communication in the presence of a horizon

Su, Daiqin and Ralph, T. C. (2014). Quantum communication in the presence of a horizon. Physical Review D - Particles, Fields, Gravitation and Cosmology, 90 (8) 084022, 084022-1-084022-8. doi: 10.1103/PhysRevD.90.084022

Quantum communication in the presence of a horizon

2014

Journal Article

Boson sampling from a Gaussian State

Lund, A. P., Laing, A., Rahimi-Keshari, S., Rudolph, T., O'Brien, J. L. and Ralph, T. C. (2014). Boson sampling from a Gaussian State. Physical Review Letters, 113 (10) 100502, 100502.1-100502.5. doi: 10.1103/PhysRevLett.113.100502

Boson sampling from a Gaussian State

2014

Journal Article

Configurable unitary transformations and linear logic gates using quantum memories

Campbell, G. T., Pinel, O., Hosseini, M., Ralph, T. C., Buchler, B. C. and Lam, P. K. (2014). Configurable unitary transformations and linear logic gates using quantum memories. Physical Review Letters, 113 (6) 063601, 063601. doi: 10.1103/PhysRevLett.113.063601

Configurable unitary transformations and linear logic gates using quantum memories

2014

Journal Article

Spacetime effects on satellite-based quantum communications

Bruschi, David Edward, Ralph, Timothy C., Fuentes, Ivette, Jennewein, Thomas and Razavi, Mohsen (2014). Spacetime effects on satellite-based quantum communications. Physical Review D, 90 (4) 045041, 045041.1-045041.13. doi: 10.1103/PhysRevD.90.045041

Spacetime effects on satellite-based quantum communications

2014

Journal Article

Experimental simulation of closed timelike curves

Ringbauer, Martin, Broome, Matthew A., Myers, Casey R., White, Andrew G. and Ralph, Timothy C. (2014). Experimental simulation of closed timelike curves. Nature Communications, 5 (1) 4145, 4145. doi: 10.1038/ncomms5145

Experimental simulation of closed timelike curves

2014

Journal Article

Entanglement-free certification of entangling gates

Almeida, M. P., Gu, Mile, Fedrizzi, Alessandro, Broome, Matthew A., Ralph, Timothy C. and White, Andrew G. (2014). Entanglement-free certification of entangling gates. Physical Review A, 89 (4) 042323, 042323.1-042323.5. doi: 10.1103/PhysRevA.89.042323

Entanglement-free certification of entangling gates

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

    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

    Quantum mechanics near closed timelike curves

    Principal Advisor

  • Doctor Philosophy

    Beyond quantum field theory on a curved background

    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

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