Hlér Kristjánsson

hler.kristjansson
Joint Postdoctoral Research Fellow - Perimeter/UW(Institute for Quantum Computing)
Perimeter Institute for Theoretical Physics
***If you are an undergraduate or masters' student interested in working with me on a summer internship/masters' project please feel free to contact me via email!***<br /><br />Student supervision: <br />6. Thomas Vinet, external Masters' thesis from Télécom Paris, at Perimeter Institute. Primary supervisor, Feb. 2024-present.<br />5. Yangchen Zhou, Undergraduate Research Project, Institute for Quantum Computing, University of Waterloo. Primary supervisor, Sept. 2023-present.<br />4. Tatsuki Odake, Higher-order quantum transformations of Hamiltonian dynamics, MSc Thesis in Physics, University of Tokyo,<br />2022–24. Co-supervisor with Prof Mio Murao.<br />3. Yan Zhong, Undergraduate Summer Research Project, Department of Computer Science, The University of Hong Kong,<br />2020. Co-supervisor with Prof Giulio Chiribella.<br />2. Anthony Munson, Communication advantages for the superposition of asymptotically long sequences of quantum channels,<br />MSc Thesis in Computer Science, University of Oxford, 2020. Co-supervisor with Prof Giulio Chiribella.<br />1. Wenxu (Mike) Mao, Quantum superposition of communication lines, BSc Thesis in Computer Science, The University of Hong<br />Kong, 2019. Co-supervisor with Prof Giulio Chiribella.<br /><br />Tutorials:<br />2. Class Tutor for the Quantum Computer Science MSc Course, University of Oxford Oct. 2019 – Dec. 2019.<br />1. Class Tutor for the Quantum Information BSc Course, University of Oxford Jan. 2019 – Mar. 2019.
I am interested in the foundational structures of quantum theory and how they can be used in novel ways for advantages in quantum information processing. Specifically, my research interests are currently in higher-order quantum computation (the quantum analogue of functional programming) and quantum causality, including applications in Hamiltonian simulation and machine learning. In the past few years, I have worked on the following topics: causality in quantum theory, indefinite causal order, higher-order quantum algorithms, Hamiltonian simulation, quantum communication with coherent control of transmission lines, quantum resource theories, quantum diagrammatic languages, quantum machine learning and quantum neural networks.
  • Odake, T., Kristjánsson, H., Soeda, A., & Murao, M. (2024). Higher-order quantum transformations of Hamiltonian dynamics. Physical Review Research, 6(1), l012063. doi:10.1103/physrevresearch.6.l012063
  • Odake, T., Kristjánsson, H., Taranto, P., & Murao, M. (2023). Universal algorithm for transforming Hamiltonian eigenvalues. arxiv:2312.08848v3
  • Kristjánsson, H., Zhong, Y., Munson, A., & Chiribella, G. (2022). Quantum networks with coherent routing of information through multiple nodes. arxiv:2208.00480v2
  • Vanrietvelde, A., Ormrod, N., Kristjánsson, H., & Barrett, J. (2022). Consistent circuits for indefinite causal order. arxiv:2206.10042v2
  • Howl, R., Akil, A., Kristjánsson, H., Zhao, X., & Chiribella, G. (2022). Quantum gravity as a communication resource. arxiv:2203.05861v2
  • Kristjánsson, H., Mao, W., ???., & Chiribella, G. (2021). Witnessing latent time correlations with a single quantum particle. Physical Review Research, 3(4), 043147. doi:10.1103/physrevresearch.3.043147
  • Vanrietvelde, A., Kristjánsson, H., & Barrett, J. (n.d.). Routed quantum circuits. Quantum, 5, 503. doi:10.22331/q-2021-07-13-503
  • Rubino, G., Rozema, L. A., Ebler, D., Kristjánsson, H., Salek, S., Guérin, P. A., . . . Walther, P. (2021). Experimental quantum communication enhancement by superposing trajectories. Physical Review Research, 3(1), 013093. doi:10.1103/physrevresearch.3.013093
  • Higher-order transformations and the causal structure of quantum processes, Quantum Foundations, 2023/10/06, PIRSA:23100106
  • Quantum gravity as a communication resource, QPL 2023, Henri Poincaré Institute, Paris, France, 2023/07/17
  • Higher-order quantum transformations of Hamiltonian dynamics, Inria Saclay - Île-de-France Research Centre, Paris, France, 2023/07/13
  • Introduction to Indefinite Causal Order, Benasque Quantum Information 2023, Centro Ciencias de Benasque Pedro Pascual, Benasque, Spain, 2023/06/29
  • Witnessing latent time correlations with a single quantum particle, University of Geneva, Geneva, Switzerland, 2023/04/24
  • Quantum gravity as a communication resource, QISS Spring School 2023, Château de Goutelas, France, 2023/04/18