The projects and published results in this group deal with quantum control of spin networks.

We investigate robust quantum control of spin networks, specifically focused on energy landscape control, using a range of optimisation and control approaches from gradient-based optimisation to reinforcement learning. We also study approaches to describe and characterise the network dynamics and process tomography techniques.

People

• Frank C Langbein, School of Computer Science and Informatics, Cardiff University; langbein.org
• Sophie Schirmer, Physics, Swansea University
• Carrie A Weidner, Quantum Engineering Technology Laboratories, University of Bristol
• Edmond Jonckheere, Department of Electrical and Computer Engineering, University of Southern California
• Paul Bogdan, Department of Electrical and Computer Engineering, University of Southern California
• Sean O'Neil, Electrical Engineering and Computer Science Department of the United States Military Academy, West Point; Department of Electrical and Computer Engineering, University of Southern California
• Kirill Sidorov, School of Computer Science and Informatics, Cardiff University
• Max Chandler, School of Computer Science and Informatics, Cardiff University
• Benedict Uttley, School of Computer Science and Informatics, Cardiff University
• Konstantinos Dimou, School of Computer Science and Informatics, Cardiff University
• Peter Davison, School of Computer Science and Informatics, Cardiff University
• Anastasia Ugaste, School of Computer Science and Informatics, Cardiff University
• Irtaza Khalid, School of Computer Science and Informatics, Cardiff University
• Jayant Misra, School of Computer Science and Informatics, Cardiff University

Publications

• S. P. O'Neil, C. A. Weidner, E. A. Jonckheere, F. C. Langbein, S. G. Schirmer. Robustness of Dynamic Quantum Control: Differential Sensitivity Bounds. Preprint, 2023. [arXiv:2401.00301] [PDF] [Details]

• C. A. Weidner, E. A. Reed, J. Monroe, S. O'Neil, E. Maas, E. A. Jonckheere, F. C. Langbein, S. G. Schirmer. Robust Quantum Control in Closed and Open Systems: Theory and Practice. Preprint, 2023. [arXiv:2401.00294] [PDF] [Details]

• FC Langbein. Finding and Characterising Robust Quantum Controls. Faculti interview with Frank Langbein on robust quantum control, 25th May 2023. [URL: https://faculti.net/finding-and-characterising-robust-quantum-controls/]

• E Jonckheere, SG Schirmer, FC Langbein, CA Weidner, S O'Neil. Disturbance-agnostic robust performance with structured uncertainties and initial state error in classical versus quantum oscillatory systems. Preprint, 2023. [arXiv:2305.03918] [PDF] [Details]

• I Khalid, CA Weider, EA Jonckheere, SG Shermer, FC Langbein. Sample-efficient Model-based Reinforcement Learning for Quantum Control. Phys. Rev. Research 5, 043002, 2023. [DOI:10.1103/PhysRevResearch.5.043002] [arXiv:2304.09718] [PDF] [Details]

• SP O'Neil, I Khalid, AA Rompokmos, CA Weidner, FC Langbein, S Schirmer, EA Jonckmheere. Analyzing and Unifying Robustness Measures for Excitation Transfer Control in Spin Networks. IEEE Control Systems Letters, 7:1783-1788, 2023. Also accepted for presentation at the IEEE Conf. Decision and Control (CDC) 2023. [DOI:10.1109/LCSYS.2023.3279797] [arXiv:2303.09518] [PDF] [Details]

• SP O'Neil, FC Langbein, E Jonckheere, SG Shermer. Robustness of Energy Landscape Control to Dephasing. Research Directions: Quantum Technologies, 1, E13, 2023. [doi:10.1017/qut.2023.6] [arXiv:2303.05649] [PDF] [Video Abstract] [Details]

• S O'Neil, FC Langbein, E Jonckheere, SG Shermer. Robustness of Energy Landscape Controllers for Spin Rings under Coherent Excitation Transport. Research Directions: Quantum Technologies, Volume 1, e12, 2023. [DOI:10.1017/qut.2023.5] [arXiv:2303.00142] [PDF] [Video Abstract] [Details]

• S O'Neil, SG Schirmer, FC Langbein, CA Weidner, E Jonckheere. Time Domain Sensitivity of the Tracking Error. IEEE Transactions on Automatic Control, 2023. [DOI:10.1109/TAC.2023.3331681] [arXiv:2210.15783] [PDF] [Details]

• CA Weidner, SG Schirmer, FC Langbein, EA Jonckheere. Applying Classical Control Techniques to Quantum Systems: Entanglement versus Stability Margin and other Limitations. IEEE Conf Decision and Control, pp. 5813-5818, 2022. [DOI:10.1109/CDC51059.2022.9992337] [arXiv:2207.12385] [PDF] [Details]. A video presenting this paper is on YouTube.

• AA Rompokos, FC Langbein, EA Jonckheere. Information Transfer in Spintronics Networks under Worst Case Uncertain Parameter Errors. IEEE Conf Decision and Control, pp. 5825-5830, 2022. [DOI:10.1109/CDC51059.2022.9993088] [PDF] [Details]

• Irtaza Khalid, Carrie Weidner, S.G. Schirmer, Edmond Jonckheere, Frank C. Langbein. Sample-efficient Model-based Reinforcement Learning for Quantum Control. Poster at BQIT:23, 2023. [PDF:poster]

• I. Khalid, C. A. Weidner, E. A. Jonckheere, S. G. Shermer, F. C. Langbein. Statistically Characterising Robustness and Fidelity of Quantum Controls and Quantum Control Algorithms. Phys. Rev. A, 107, 032606, 2023. [DOI:10.1103/PhysRevA.107.032606] [arXiv:2207.07801] [PDF] [Details]

• E. Jonckheere, S. G. Schirmer, F. C. Langbein, C. A. Weidner. Noiseless Robust Performance with Structured Uncertainties and Initial State Error. Preprint, 2022 [PDF:paper] [Details]

• SG Schirmer, FC Langbein, CA Weidner, EA Jonckheere. Robust Control Performance for Open Quantum Systems. IEEE Trans Automatic Control, 67(11):6012-6024, 2022. [DOI:10.1109/TAC.2022.3181249] [arXiv:2008.13691] [PDF:paper] [Details]

• Irtaza Khalid, Carrie Weidner, S.G. Schirmer, Edmond Jonckheere, Frank C. Langbein. Finding and Characterising Robust Quantum Controls. Poster at BQIT:22, 2022. [PDF:poster]

• F.C. Langbein. AI3SD Video: Learning to Control Quantum Systems Robustly, 10/11/2021. AI3SD Autumn Seminar Series 2021. 13 Oct - 15 Dec 2021. [PDF] [Video] [DOI:10.5258/SOTON/AI3SD0163]

• SG Schirmer, FC Langbein, CA Weidner, EA Jonckheere. Robustness of Quantum Systems Subject to Decoherence: Structured Singular Value Analysis?. IEEE Conf Decision and Control, pp. 4158-4163, 2021. [DOI:10.1109/CDC45484.2021.9682796] [arXiv:2110.05372] [PDF:paper] [Details]

• I Khalid, CA Weidner, EA Jonckheere, SG Schirmer, FC Langbein. Reinforcement Learning vs. Gradient-Based Optimisation for Robust Energy Landscape Control of Spin-1/2 Quantum Networks. IEEE Conf Decision and Control, pp. 4133-4139, 2021. [DOI:10.1109/CDC45484.2021.9683463] [arXiv:2109.07226] [PDF:paper] [Details]

• Irtaza Khalid, Carrie Weidner, S.G. Schirmer, Edmond Jonckheere, Frank C. Langbein. Finding and Characterising Robust Quantum Controls. European Quantum Technologies Conference EQTC, 2021. [PDF:poster] [PDF:abstract]

• EA Jonckheere, SG Schirmer, FC Langbein. Effect of Quantum Mechanical Global Phase Factor on Error vs Sensitivity Limitation in Quantum Routing. IEEE Conf Decision and Control, pp. 1339-1344, 2019. [DOI:10.1109/CDC40024.2019.9029913] [PDF:paper] [Details]

• SG Schirmer, EA Jonckheere, S O’Neil, FC Langbein. Robustness of energy landscape control for spin networks under decoherence. IEEE Conf Decision and Control, pp. 6608-6613, 2018. [DOI:doi.org/10.1109/CDC.2018.8619179] [arXiv:1808.01256] [PDF:paper] [Details]

• EA Jonckheere, SG Schirmer, FC Langbein. Cover Image. Int J Robust and Nonlinear Control, 28(6), 2018. [DOI:10.1002/rnc.4085] [Details]

• S O’Neil, EA Jonckheere, SG Schirmer, FC Langbein. Sensitivity and Robustness of Quantum Spin-1/2 Rings to Parameter Uncertainty. IEEE Conf Decision and Control, pp. 6137-6142, 2017. [DOI:10.1109/CDC.2017.8264584] [arXiv:1708.09649] [PDF:paper] [Details]

• EA Jonckheere, SG Schirmer, FC Langbein. Structured Singular Value Analysis for Spintronics Network Information Transfer Control. IEEE Trans Automatic Control, 62(12):6568-6574, 2017. [DOI:10.1109/TAC.2017.2714623] [arXiv:1706.03247] [PDF:paper] [Details]

• EA Jonckheere, SG Schirmer, FC Langbein. Jonckheere-Terpstra test for nonclassical error versus log-sensitivity relationship of quantum spin network controllers. Int J Robust and Nonlinear Control, 28(6):2383-2403, 2018. [DOI:10.1002/rnc.4022] [arXiv:1612.02784] [PDF:paper] [Details]

• P Bogdan, EA Jonckheere, SG Schirmer. Multi-fractal Geometry of Finite Networks of Spins. Chaos, Solitons and Fractals, 103:622-631, 2017. [DOI:10.1016/j.chaos.2017.07.008] [arXiv:1608.08192] [PDF:paper] [Details]

• SG Schirmer, EA Jonckheere, FC Langbein. Design of Feedback Control Laws for Information Transfer in Spintronics Networks. IEEE Trans Automatic Control, 63(8):2523-2536, 2018. [DOI:10.1109/TAC.2017.2777187] [arXiv:1607.05294] [PDF:paper] [Details]

• FC Langbein, SG Schirmer, EA Jonckheere. Time optimal information transfer in spintronics networks. IEEE Conf Decision and Control, pp. 6454-6459, 2015. [DOI:10.1109/CDC.2015.7403236] [arXiv:1508.00928] [PDF:paper] [Details]

• EA Jonckheere, FC Langbein, SG Schirmer. Information Transfer Fidelity in Spin Networks and Ring-based Quantum Routers. Quantum Information Processing, 14(12):4761-4785, 2015. [DOI:10.1007/s11128-015-1136-4] [arXiv:1408.3765] [PDF:paper] [Details]

• SG Schirmer, FC Langbein. The ubiquitous problem of learning system parameters for dissipative two-level quantum systems: Fourier analysis versus Bayesian estimation. Phys Rev A, 91:022125, 2015. [DOI:10.1103/PhysRevA.91.022125] [arXiv:1412.4282] [PDF:paper] [Details]

• SG Schirmer, FC Langbein. Characterization and Control of Quantum Spin Chains and Rings. Int Symp Communications, Control and Signal Processing, pp. 615 – 619, 2014. [DOI:10.1109/ISCCSP.2014.6877950] [arXiv:1403.0226] [PDF:paper] [Details]

• EA Jonckheere, FC Langbein, SG Schirmer. Quantum networks: Anti-core of spin chains. Quantum Information Processing, 13(7):1607-1637, 2014. [DOI:10.1007/s11128-014-0755-5] [arXiv:1403.0159] [PDF:paper] [Details]

• EA Jonckheere, FC Langbein, SG Schirmer. Curvature of quantum rings. Int Symp Communications Control and Signal Processing, pp. 1-6, 2012. [DOI:10.1109/ISCCSP.2012.6217863] [arXiv:1202.2556] [PDF:paper] [Details]

• EA Jonckheere, SG Schirmer, FC Langbein. Geometry and Curvature of Spin Networks. IEEE Int Conf Control Applicatons, pp. 786-791, 2011. [DOI:10.1109/CCA.2011.6044395] [arXiv:1102.3208] [PDF:paper] [Details]

• FC Langbein, SG Schirmer. Quantum Engineering: From Einstein’s Spooky Action to Sustainable Technology? IEEE GOLDRush newsletter, peer-reviewed contribution, pp. 14-15, September 2010. [DOI:10.13140/RG.2.1.4109.1921] [Published] [PDF:paper] [Details]

• SG Schirmer, FC Langbein. Quantum System Identification: Hamiltonian Estimation using Spectral and Bayesian Analysis. Int Symp Communications, Control and Signal Processing, pp. 1-5, 2010. [DOI:10.1109/ISCCSP.2010.5463437] [arXiv:0911.5429] [PDF:paper] [Details]

PhDs

• Irtaza Khalid. Robust Quantum Control and Reinforcement Learning. School of Computer Science and Informatics, Cardiff University.
• Sean O'Neil. Robust Control of Quantum Systems. Department of Electrical Engineering. University of Southern California.

Reports

• J Misra, FC Langbein. Analysing the Robustness of Controllers for Information Transfer in Quantum Spin-1/2 Networks. Summer Research Internship in Quantum Control at Cardiff University, 2022. [https://jayantmisra.github.io/analysing-robustness-of-controls/]

• V Manivasagam. Quantum Error Correction vs. Robust Quantum Control. MSc Advanced Computer Science, Cardiff Univerrsity, 2021.

• A Ugaste. Reinforcement Learning Algorithms for Controlling Quantum Spin-1/2 Networks. BSc Computer Science project, Cardiff University, 2021. [Archive]

• B Uttley. Quantum Spin Network Simulator. BSc Computer Science project, Cardiff University, 2019.

• K Dimou. Visualising Quantum Control Landscapes. MSc Computer Science project, Cardiff University, 2017.

• P Davison. Parallelisation of Matrix Exponentials in C++/CUDA for Quantum Control. BSc Computer Science project, Cardiff University, 2016. [Archive]

• M Chandler. Parallelising the L-BFGS algorithm on GPUs for Quantum Control problems. BSc Computer Science project, Cardiff University, 2015. [Archive]

Code

• SP O'Neil, I Khalid, SM Shermer, FC Langbein. Code - Robustness of Energy Landscape Control - Sensitivity vs RIM. Code, https://github.com/qyber-black/code-robustness-of-energy-landscape-control-sensitivity-vs-rim, V1.0, 15th January 2024. [Project]

• S.M. Shermer, S.P. O'Neil. Differential Sensitivity Bounds for Dynamic Quantum Control. Code, https://github.com/qyber-black/Code-Differential-Sensitivity-Bounds-for-Dynamic-Control, V1.0.0, 4th January 2024. [Project]

• I. Khalid, C. A. Weidner, E. A. Jonckheere, S. G. Shermer, F. C. Langbein. RobChar: Robust Characterisation of Quantum Controls and Control Algorithms. Code, https://github.com/qyber-black/code-robchar, 22nd July 2022. [DOI:10.5281/zenodo.6891152] [Project]

• I Khalid. Reinforcement Learning for Quantum Control and Robustness Analysis. pre-alpha.

• SG Shermer. Mu Analysis for Quantum Systems. pre-alpha.

• FC Langbein, CA Weidner, SG Shermer, E Jonckheere. PySpinNet, pre-alpha. (including DMD/Fresnel and SpinNetIBM)

• FC Langbein, SG Shermer, S O'Neil. E Jonckheere. MatSpinNet. Code, https://github.com/qyber-black/Code-MatSpinNet. [DOI:10.6084/m9.figshare.21856911] [Project]

Data

• SP O'Neil, I Khalid, SM Shermer, FC Langbein. Robustness of Energy Landscape Control - Sensitivity vs RIM. Results data, https://qyber.black/spinnet/results-robustness-of-energy-landscape-control-sensitivity-vs-rim, Version 1.0, 15th January 2024.

• SP O'Neil, FC Langbein, SG Shermer. Robustness of Energy Landscape Controllers for XX Spin Rings. Cambridge Open Engage. Dataset, 2023. [DOI:10.33774/coe-2023-x52n7] This is a summary of

  • FC Langbein, SP O’Neil, SG Shermer. Results - Energy Landscape Controllers for XX Spin Rings - Robustness. Dataset, 2023. [Repository:https://qyber.black/spinnet/results-elc-xx-rings-robustness]
  • FC Langbein, SP O’Neil, SG Shermer. Data - Energy Landscape Controllers for XX Spin Rings. Dataset, 2023. [Repository:https://qyber.black/spinnet/data-elc-xx-rings]

• FC Langbein, S O’Neil, SG Schirmer. Energy landscape controllers for quantum state transfer in spin-1/2 networks with ring topology, Research Directions, Cambridge Open Engage, 2023. [DOI:10.33774/coe-2022-35xgg] [Details] [Repository:https://qyber.black/spinnet/data-static-bias-controllers-xx-spin-rings] [Repisotory-Mirror:https://github.com/qyber-black/Data-Static-Bias-Controllers-XX-Spin-Rings]
  An older version of this dataset has been published here: FC Langbein, SG Schirmer, EA Jonckheere. Static Bias Controllers for XX Spin-1/2 Rings. Data set, figshare, 3rd July 2016. [DOI:10.6084/m9.figshare.3485240.v1] [FeedbackControlLaws20160703.zip]

Workshops

• Quantum Technology: Computational Models for Quantum Device Design (12w5061). Banff International Research Stations for Mathematical Innovation and Discovery, January 8-13, 2012. [Details]

• NSEW 2008: Quantum Engineering. Practical Applications of Quantum Physics and How these Might Transform Society. A lecture on the fundamentals of quantum physics with hands-on demonstrations and a discussion of the potential impact of quantum technology on everyone’s life. [Details]

Funding

• October 2020, 3 years: Cardiff University, School of Computer Science and Informatics PhD Scholarship. Irtaza Khalid.

• September 2018 – August 2020: US-UK International Student Research in Robust Control of Quantum Networks. PI: EA Jonckheere (University of Southern California) with SG Schirmer (Swansea University) and FC Langbein (Cardiff University). NSF #1829078 OISE IRES ASI – Track II. USD164,503. [Details]

• August 2014 – August 2015: Cardiff University Research Leave Fellowship. PI: FC Langbein (Cardiff University). Teaching replacement costs and £3,000 support. [Details]

• August 2012 – July 2015: QUAINT – Optimal Control Technologies in Quantum Information Processing. Coordinator: University of Southampton (I. Kuprov) with Univerzita Karlova v Praze, Czech Republic, Universität Ulm, Germany, Karlsruher Institut fuer Technologie, Germany, Universität des Saarlandes, Germany, Universität Kassel, Germany, Technisch Universität München, Germany, Aarhus Universitet, Denmark, Universite de Bourgogne, France, Centre National de la Recherche Scientifique, France, The Hebrew University of Jerusalem, Israel, Weizmann Institute of Science, Israel, The University of Nottingham, UK, Cardiff University, UK, Swansea University, UK. FP7-ICT-2011-C, ICT-2011.9.1 – Challenging current Thinking, CSA – Coordination & support action, ref 297861. EUR 399,901. [Details]

• 2009-2013: RIVIC: One Wales Research Institute for Visual Computing. WAG (HEFCW) via Bangor University. Consortium: RR Martin, NJ Avis, AD Marshall, PL Rosin, FC Langbein at Cardiff University, with Bangor University (lead), Aberystwyth University, Swansea University. £998,011. [Details]

• 2008: Quantum engineering – practical applications of quantum physics and how these might transform society. PI: FC Langbein (Cardiff University) with SG Schirmer (Swansea University). Welsh Assembly Government via the BA, National Science and Engineering Week. £500. [Details]

Locations

The wiki is written and maintained on Qyber\black at https://qyber.black/pca/info-spinnet/

Contact

For any general enquiries relating to this project group, send an e-mail.

License

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The publications, code, data, etc. may be under a different license. Check the relevant information provided with these products.