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)

261 - 280 of 430 works

2006

Journal Article

Modelling photo-detectors in quantum optics

Rohde, P. P. and Ralph, T. C. (2006). Modelling photo-detectors in quantum optics. Journal Of Modern Optics, 53 (11), 1589-1603. doi: 10.1080/09500340600578369

Modelling photo-detectors in quantum optics

2006

Conference Publication

A complete quantum cryptographic system using a continuous wave laser

Sharma, Vikram, Lance, Andrew M., Symul, Thomas, Weedbrook, Christian, Ralph, Timothy C. and Lam, Ping Koy (2006). A complete quantum cryptographic system using a continuous wave laser. Conference on Microelectronics - Design, Technology and Packaging II, Brisbane Australia, Dec 12-14, 2005. BELLINGHAM: SPIE-INT SOC OPTICAL ENGINEERING. doi: 10.1117/12.651721

A complete quantum cryptographic system using a continuous wave laser

2006

Journal Article

Quantum nondemolition measurements for quantum information (vol 73, 012113, 2006)

Ralph, T. C., Bartlett, S. D., O'Brien, J. L., Pryde, G. J. and Wiseman, H. M. (2006). Quantum nondemolition measurements for quantum information (vol 73, 012113, 2006). Physical Review a, 73 (3). doi: 10.1103/PhysRevA.73.039902

Quantum nondemolition measurements for quantum information (vol 73, 012113, 2006)

2006

Journal Article

Coherent-state quantum key distribution without random basis switching

Weedbrook, Christian, Lance, Andrew M., Bowen, Warwick P., Symul, Thomas, Ralph, Timothy C. and Lam, Ping Koy (2006). Coherent-state quantum key distribution without random basis switching. Physical Review A, 73 (2) 022316, 022316-1-022316-7. doi: 10.1103/PhysRevA.72.022316

Coherent-state quantum key distribution without random basis switching

2006

Conference Publication

Homodyne measurement of average photon number

Webb, J. G., Ralph, T. C. and Huntington, E. H. (2006). Homodyne measurement of average photon number. Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference, CLEO/QELS 2006, , , May 21, 2006-May 26, 2006. Optical Society of America. doi: 10.1109/CLEO.2006.4628675

Homodyne measurement of average photon number

2006

Journal Article

Conditional quantum-state engineering using ancillary squeezed-vacuum states

Jeong, Hyunseok, Lance, Andrew M., Grosse, Nicolai B., Symul, Thomas, Lam, Ping Koy and Ralph, Timothy C. (2006). Conditional quantum-state engineering using ancillary squeezed-vacuum states. Physical Review A, 74 (3) 033813, 033813-1-033813-10. doi: 10.1103/PhysRevA.74.033813

Conditional quantum-state engineering using ancillary squeezed-vacuum states

2006

Journal Article

Quantum-state engineering with continuous-variable postselection

Lance, Andrew M., Jeong, Hyunseok, Grosse, Nicolai B., Symul, Thomas, Ralph, Timothy C. and Lam, Ping Koy (2006). Quantum-state engineering with continuous-variable postselection. Physical Review A, 73 (4) 041801, 041801-1-041801-4. doi: 10.1103/PhysRevA.73.041801

Quantum-state engineering with continuous-variable postselection

2006

Conference Publication

Efficient coherent state quantum computing by adaptive measurements

Lund A.P. and Ralph T.C. (2006). Efficient coherent state quantum computing by adaptive measurements. Quantum Electronics and Laser Science Conference, QELS 2006, Long Beach, CA, May 21, 2006-May 21, 2006. Optical Society of America. doi: 10.1109/CLEO.2006.4628964

Efficient coherent state quantum computing by adaptive measurements

2006

Journal Article

Practical limitations in optical entanglement purification

Rohde, Peter P., Ralph, Timothy C. and Munro, William J. (2006). Practical limitations in optical entanglement purification. Physical Review A, 73 (3) 030301, 030301-1-030301-4. doi: 10.1103/PhysRevA.73.030301

Practical limitations in optical entanglement purification

2006

Journal Article

Generation of a frequency comb of squeezing in an optical parametric oscillator

Dunlop, A. E., Huntington, E. H., Harb, C. C. and Ralph, T. C. (2006). Generation of a frequency comb of squeezing in an optical parametric oscillator. Physical Review A, 73 (1) 013817, 013817-1-013817-7. doi: 10.1103/PhysRevA.73.013817

Generation of a frequency comb of squeezing in an optical parametric oscillator

2006

Conference Publication

A model for non-linear quantum evolution based on time displaced entanglement

Ralph, T. C. (2006). A model for non-linear quantum evolution based on time displaced entanglement. Quantum Communications and Quantum Imaging IV, San Diego, USA, 13 August, 2006. Bellingham, USA: SPIE. doi: 10.1117/12.680097

A model for non-linear quantum evolution based on time displaced entanglement

2006

Journal Article

Error models for mode mismatch in linear optics quantum computing

Ralph, Timothy C. and Rohde, Peter P. (2006). Error models for mode mismatch in linear optics quantum computing. Physical Review A, 73 (6) 062312, 062312-1-062312-6. doi: 10.1103/PhysRevA.73.062312

Error models for mode mismatch in linear optics quantum computing

2006

Journal Article

Improving the fidelity of optical Zeno gates via distillation

Leung, Patrick M. and Ralph, Timothy C. (2006). Improving the fidelity of optical Zeno gates via distillation. Physical Review A, 74 (6) 062325, 062325-1-062325-6. doi: 10.1103/PhysRevA.74.062325

Improving the fidelity of optical Zeno gates via distillation

2006

Book Chapter

Quantum State Sharing

Symul, T., Lance, A. M., Bowen, W. P., Lam, P. K., Sanders, B. C. and Ralph, T. C. (2006). Quantum State Sharing. Quantum Communications and Cryptography. (pp. 163-186) edited by A. Sergienko. New York: Taylor & Francis.

Quantum State Sharing

2006

Journal Article

Homodyne measurement of the average photon number

Webb, J. G., Ralph, T. C. and Huntington, E. H. (2006). Homodyne measurement of the average photon number. Physical Review A, 73 (3) 033808, 033808-1-033808-7. doi: 10.1103/PhysRevA.73.033808

Homodyne measurement of the average photon number

2006

Journal Article

Quantum nondemolition measurements for quantum information

Ralph, T. C., Bartlett, S. D., O'Brien, J. L., Pryde, G. J. and Wiseman, H. M. (2006). Quantum nondemolition measurements for quantum information. Physical Review A, 73 (1) 012113, 012113.1-012113.11. doi: 10.1103/PhysRevA.73.012113

Quantum nondemolition measurements for quantum information

2006

Journal Article

Transfer of nonclassical properties from a microscopic superposition to macroscopic thermal states in the high temperature limit

Jeong, H. and Ralph, T. C. (2006). Transfer of nonclassical properties from a microscopic superposition to macroscopic thermal states in the high temperature limit. Physical Review Letters, 97 (10) 100401, 100401-1-100401-4. doi: 10.1103/PhysRevLett.97.100401

Transfer of nonclassical properties from a microscopic superposition to macroscopic thermal states in the high temperature limit

2006

Journal Article

Quantum optical systems for the implementation of quantum information processing

Ralph, T. C. (2006). Quantum optical systems for the implementation of quantum information processing. Reports On Progress In Physics, 69 (4), 853-898. doi: 10.1088/0034-4885/69/4/R01

Quantum optical systems for the implementation of quantum information processing

2005

Conference Publication

Successful quantum key distribution with simultaneous quadrature measurement in the presence of 90% line loss

Symul, T., Lance, A. M., Sharma, V., Lam, P. K., Weedbrook, C. and Ralph, T. C. (2005). Successful quantum key distribution with simultaneous quadrature measurement in the presence of 90% line loss. doi: 10.1109/EQEC.2005.1567468

Successful quantum key distribution with simultaneous quadrature measurement in the presence of 90% line loss

2005

Conference Publication

Using entanglement in photonic qubit measurements

Pryde, G. J., O'Brien, J. L., White, A. G., Ralph, T. C., Bartlett, S. D. and Wiseman, H. M. (2005). Using entanglement in photonic qubit measurements. Optics and photonics 2005: Quantum Communications and Quantum Imaging III, San Diego, CA, United States, 31 July - 4 August 2005. Bellingham, WA, United States: S P I E - International Society for Optical Engineering. doi: 10.1117/12.616166

Using entanglement in photonic qubit measurements

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

    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

    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

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