Quantum information and communication technology is the fundamental backbone for larger quantum networks that can consist of clusters quantum cryptographic, computing, and/or sensing nodes. The advantage of such networks over their classical counterparts lies in their ability to exploit the more delicate systems that are permitted by quantum mechanics. Quantum cryptographic systems have the advantage of mathematically provable security and privacy, fundamentally addressing the increasing security threat to communication caused by the advancement of information and communications technologies. In recent years quantum cryptography has been the subject of intense research and rapid progress, and it has demonstrated great potential to become the key technology to maintain privacy of communication. The quantum information theory and security group at QSI aims to develop necessary theories and technologies for the implementation of quantum-enhanced networks.
Key Members: Prof Runyao Duan, Prof Yuan Feng, Dr Marco Tomamichel
Quantum information theory
This research aims to further advance quantum Shannon theory – how information can be compressed, transmitted, and manipulated more efficiently and faithfully in the quantum world. Another major research focus is to develop a quantitative theory of entanglement, and to apply entanglement as a resource in various scenarios such as communication and error correcting codes design.
Quantum communication and networking
Evaluating how well a quantum communication system performs in practical domains has become a pressing matter. Our primary goal is to introduce measurable benchmarks for quantum communication system proposals, which will provide invaluable information to potential stakeholders, standards makers and technology providers.
This research aims to quantify a quantum channel's capability for secure communications. Expected outcomes will significantly advance the theory of quantum cryptography and our knowledge of the fundamental resource of secret keys, have immediate application for the classical security of existing (non- quantum) communication devices, and benefit security, military, government, industry, individuals, and the community.
- Xin Wang*, Wei Xie* and Runyao Duan. Semidefinte programming strong converse bounds for quantum channel capacities. QIP 2017.
- Eric Chitambar and Min-Hsiu Hsieh. Round complexity in the local transformations of quantum and classical state. QIP 2017.
- Runyao Duan and Andreas Winter. No-signalling assisted zero-error capacity of quantum channels and an information theoretic interpretation of the Lovász number. IEEE Trans. Inf. Theory (2016) (Earlier version: QIP 2015).
- Eric Chitambar, Ben Fortescue, and Min-Hsiu Hsieh. Distributions attaining secret key at a rate of the conditional mutual information. CRYPTO 2015.
- Runyao Duan, Simone Severini, and Andreas Winter. Zero-error communication via quantum channels, noncommutative graphs, and a quantum Lovász number. IEEE Trans. Inf. Theory (2013).
- Todd Brun, Igor Devetak, and Min-Hsiu Hsieh. Correcting quantum errors with entanglement. Science (2006).
* current QSI PhD students.