ORCID Profile
0000-0003-0965-9509
Current Organisation
University Of Strathclyde
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Publisher: Elsevier BV
Date: 04-2012
Publisher: American Physical Society (APS)
Date: 28-08-2003
Publisher: Institution of Engineering and Technology (IET)
Date: 19-07-2021
DOI: 10.1049/QTC2.12015
Publisher: American Physical Society (APS)
Date: 19-08-2005
Publisher: Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik GmbH, Wadern/Saarbruecken, Germany
Date: 2013
Publisher: American Physical Society (APS)
Date: 15-09-2003
Publisher: Institution of Engineering and Technology (IET)
Date: 19-08-2021
DOI: 10.1049/QTC2.12019
Publisher: Informa UK Limited
Date: 11-2000
Publisher: American Physical Society (APS)
Date: 02-10-2000
Publisher: American Physical Society (APS)
Date: 15-05-2014
Publisher: IOP Publishing
Date: 23-10-2017
Publisher: American Physical Society (APS)
Date: 15-10-2015
Publisher: Informa UK Limited
Date: 15-11-2016
Publisher: IOP Publishing
Date: 03-2008
Publisher: World Scientific Pub Co Pte Lt
Date: 10-08-2001
DOI: 10.1142/S0217751X0100492X
Abstract: "Information is physical and any processing of information is always performed by physical means," an innocent-sounding statement, but its consequences are profound. When quantum effects become important, for ex le, at the level of single atoms and photons, the classical theory of computation becomes fundamentally inadequate. Entirely new modes of computation and information processing become possible. In the last few years there has been an explosion of theoretical and experimental research in quantum computation. In this brief review we describe some of these developments.
Publisher: American Physical Society (APS)
Date: 19-05-2004
Publisher: IOP Publishing
Date: 07-2022
Abstract: Terrestrial free-space (FS) quantum key distribution (QKD) is ideally suited for deployment in dense urban environments. The transition from laboratory to commercial deployment, however, raises a number of important engineering and deployment issues. Here, we investigate these issues for efficient BB84 using a weak coherent pulse-decoy state protocol. We calculate expected key lengths for different environmental conditions and when the scope for optimisation of protocol parameters is restricted due to practical considerations. In particular, we find that for a fixed receiver basis choice probability, it can be advantageous to allow the transmitter to have a different basis choice probability depending on varying channel loss and background light levels. Finally, we examine the effects of pulse intensity uncertainty finding that they can dramatically reduce the key length. These results can be used to determine the loss budget for the FS optics of a QKD systems and assist in their design.
Publisher: The Optical Society
Date: 10-2012
Publisher: American Physical Society (APS)
Date: 18-01-2005
Publisher: American Physical Society (APS)
Date: 12-12-2002
Publisher: Frontiers Media SA
Date: 10-2020
Publisher: Springer Science and Business Media LLC
Date: 09-2014
Publisher: Elsevier BV
Date: 03-2002
Publisher: American Physical Society (APS)
Date: 06-05-2008
Publisher: Pleiades Publishing Ltd
Date: 02-04-2010
Publisher: OSA
Date: 2016
Publisher: Springer Science and Business Media LLC
Date: 18-10-2016
Publisher: Elsevier BV
Date: 08-2009
Publisher: IOP Publishing
Date: 29-10-2007
Publisher: American Physical Society (APS)
Date: 27-06-2006
Publisher: American Physical Society (APS)
Date: 31-05-2016
Publisher: SPIE
Date: 22-10-2015
DOI: 10.1117/12.2199037
Publisher: IOP Publishing
Date: 19-04-2011
Publisher: Springer Science and Business Media LLC
Date: 16-02-2022
DOI: 10.1038/S41534-022-00525-3
Abstract: Global quantum communications will enable long-distance secure data transfer, networked distributed quantum information processing, and other entanglement-enabled technologies. Satellite quantum communication overcomes optical fibre range limitations, with the first realisations of satellite quantum key distribution (SatQKD) being rapidly developed. However, limited transmission times between satellite and ground station severely constrains the amount of secret key due to finite-block size effects. Here, we analyse these effects and the implications for system design and operation, utilising published results from the Micius satellite to construct an empirically-derived channel and system model for a trusted-node downlink employing efficient Bennett-Brassard 1984 (BB84) weak coherent pulse decoy states with optimised parameters. We quantify practical SatQKD performance limits and examine the effects of link efficiency, background light, source quality, and overpass geometries to estimate long-term key generation capacity. Our results may guide design and analysis of future missions, and establish performance benchmarks for both sources and detectors.
Publisher: American Physical Society (APS)
Date: 13-05-2002
Publisher: Springer Science and Business Media LLC
Date: 29-01-1997
Publisher: IOP Publishing
Date: 2023
Abstract: The objective of the proposed macroscopic quantum resonators (MAQRO) mission is to harness space for achieving long free-fall times, extreme vacuum, nano-gravity, and cryogenic temperatures to test the foundations of physics in macroscopic quantum experiments at the interface with gravity. Developing the necessary technologies, achieving the required sensitivities and providing the necessary isolation of macroscopic quantum systems from their environment will lay the path for developing novel quantum sensors. Earlier studies showed that the proposal is feasible but that several critical challenges remain, and key technologies need to be developed. Recent scientific and technological developments since the original proposal of MAQRO promise the potential for achieving additional science objectives. The proposed research c aign aims to advance the state of the art and to perform the first macroscopic quantum experiments in space. Experiments on the ground, in micro-gravity, and in space will drive the proposed research c aign during the current decade to enable the implementation of MAQRO within the subsequent decade.
Publisher: Optica Publishing Group
Date: 18-09-2020
DOI: 10.1364/AO.399227
Abstract: In this paper we present an evolution of the single-pixel camera architecture, called “pushframe,” which addresses the limitations of pushbroom cameras in space-based applications. In particular, it is well-suited to observing fast-moving scenes while retaining high spatial resolution and sensitivity. We show that the system is capable of producing color images with good fidelity and scalable resolution performance. The principle of our design broadens the choice of spectral ranges that can be captured, making it suitable for wide spectral ranges of infrared imaging.
Publisher: American Physical Society (APS)
Date: 15-08-2005
Publisher: World Scientific Pub Co Pte Lt
Date: 11-2005
DOI: 10.1142/S0219749905001304
Abstract: Almost all computational tasks in the modern computer can be designed from basic building blocks. These building blocks provide a powerful and efficient language for describing algorithms. In quantum computers, the basic building blocks are the quantum gates. In this tutorial, we will look at quantum gates that act on one and two qubits and briefly discuss how these gates can be used in quantum networks.
Publisher: American Physical Society (APS)
Date: 13-04-2009
Publisher: American Physical Society (APS)
Date: 26-07-2012
Publisher: Springer Science and Business Media LLC
Date: 10-08-2023
DOI: 10.1038/S42005-023-01299-6
Abstract: Global-scale quantum communication networks will require efficient long-distance distribution of quantum signals. While optical fibre communications are range-limited due to exponential losses in the absence of quantum memories and repeaters, satellites enable intercontinental quantum communications. However, the design of satellite quantum key distribution (SatQKD) systems has unique challenges over terrestrial networks. The typical approach to modelling SatQKD has been to estimate performances with a fully optimised protocol parameter space and with few payload and platform resource limitations. Here, we analyse how practical constraints affect the performance of SatQKD for the Bennett-Brassard 1984 (BB84) weak coherent pulse decoy state protocol with finite key size effects. We consider engineering limitations and trade-offs in mission design including limited in-orbit tunability, quantum random number generation rates and storage, and source intensity uncertainty. We quantify practical SatQKD performance limits to determine the long-term key generation capacity and provide performance benchmarks to support the design of upcoming missions.
Publisher: American Physical Society (APS)
Date: 08-03-2007
Publisher: American Physical Society (APS)
Date: 09-11-2006
Publisher: Institution of Engineering and Technology (IET)
Date: 06-09-2023
DOI: 10.1049/QTC2.12071
Publisher: Informa UK Limited
Date: 10-02-2010
Publisher: American Physical Society (APS)
Date: 21-01-2003
Publisher: American Physical Society (APS)
Date: 18-10-2006
Publisher: MDPI AG
Date: 27-02-2020
DOI: 10.3390/CRYPTOGRAPHY4010007
Abstract: Quantum key distribution (QKD) offers future proof security based on fundamental laws of physics. Long-distance QKD spanning regions such as the United Kingdom (UK) may employ a constellation of satellites. Small satellites, CubeSats in particular, in low Earth orbit are a relatively low-cost alternative to traditional, large platforms. They allow the deployment of a large number of spacecrafts, ensuring greater coverage and mitigating some of the risk associated with availability due to cloud cover. We present our mission analysis showing how a constellation comprising 15 low-cost 6U CubeSats can be used to form a secure communication backbone for ground-based and metropolitan networks across the UK. We have estimated the monthly key rates at 43 sites across the UK, incorporating local meteorological data, atmospheric channel modelling and orbital parameters. We have optimized the constellation topology for rapid revisit and thus low-latency key distribution.
Publisher: American Physical Society (APS)
Date: 26-10-2006
Publisher: American Physical Society (APS)
Date: 10-08-2010
Publisher: Springer Science and Business Media LLC
Date: 18-08-2021
DOI: 10.1038/S41534-021-00460-9
Abstract: Global-scale quantum communication links will form the backbone of the quantum internet. However, exponential loss in optical fibres precludes any realistic application beyond few hundred kilometres. Quantum repeaters and space-based systems offer solutions to overcome this limitation. Here, we analyse the use of quantum memory (QM)-equipped satellites for quantum communication focussing on global range repeaters and memory-assisted (MA-) QKD, where QMs help increase the key rate by synchronising otherwise probabilistic detection events. We demonstrate that satellites equipped with QMs provide three orders of magnitude faster entanglement distribution rates than existing protocols based on fibre-based repeaters or space systems without QMs. We analyse how entanglement distribution performance depends on memory characteristics, determine benchmarks to assess the performance of different tasks and propose various architectures for light-matter interfaces. Our work provides a roadmap to realise unconditionally secure quantum communications over global distances with near-term technologies.
Publisher: WORLD SCIENTIFIC
Date: 05-2001
Publisher: The Royal Society
Date: 28-11-2012
Abstract: The construction and operation of large-scale quantum information devices presents a grand challenge. A major issue is the effective control of coherent evolution, which requires accurate knowledge of the system dynamics that may vary from device to device. We review strategies for obtaining such knowledge from minimal initial resources and in an efficient manner, and apply these to the problem of characterization of a qubit embedded into a larger state manifold, made tractable by exploiting prior structural knowledge. We also investigate adaptive s ling for estimation of multiple parameters.
Publisher: American Physical Society (APS)
Date: 24-02-2003
Publisher: American Physical Society (APS)
Date: 05-09-2003
Publisher: American Physical Society (APS)
Date: 23-05-2013
Publisher: American Physical Society (APS)
Date: 07-01-2005
Publisher: Optica Publishing Group
Date: 25-06-2020
Abstract: Global quantum networks for secure communication can be realized using large fleets of satellites distributing entangled photon pairs between ground-based nodes. Because the cost of a satellite depends on its size, the smallest satellites will be most cost-effective. This Letter describes a miniaturized, polarization entangled, photon-pair source operating on board a nano-satellite. The source violates Bell’s inequality with a Clauser–Horne–Shimony–Holt parameter of 2.60 ± 0.06 . This source can be combined with optical link technologies to enable future quantum communication nano-satellite missions.
Publisher: American Physical Society (APS)
Date: 29-11-2006
Publisher: Cambridge University Press (CUP)
Date: 2023
DOI: 10.1017/QUT.2023.2
Abstract: Photonic quantum memories are required in many applications in quantum information science with varying performance requirements depending on specific applications. Although classical light storage has been demonstrated in time scales of minutes (Dudin et al., 2013 Heinze et al., 2013) to hours (Ma et al., 2021) in different systems, storing true single photons and single photon level coherent pulses are still limited to around a few seconds at most (Wang et al., 2021 Ortu et al., 2022 Hain et al., 2022 Stas et al., 2022). In this question, we would like to explore what the challenges for quantum memory storage for the purposes of quantum communication and the distribution of entanglement are, e.g. in quantum repeaters. Furthermore, recent work has proposed using quantum memories with hour-long storage times for quantum computation (Gouzien and Sangouard, 2021) and physically transporting single photons for astronomical interferometry (Bland-Hawthorn et al., 2021) and global quantum communications (Wittig et al., 2017 Gündoğan et al., 2023).
Publisher: Springer Science and Business Media LLC
Date: 16-06-2023
DOI: 10.1038/S41467-023-39219-5
Abstract: Quantum key distribution with solid-state single-photon emitters is gaining traction due to their rapidly improving performance and compatibility with future quantum networks. Here we emulate a quantum key distribution scheme with quantum-dot-generated single photons frequency-converted to 1550 nm, achieving count rates of 1.6 MHz with $${g}^{\\left(2\\right)}\\left(0\\right)=3.6\\%$$ g 2 0 = 3.6 % and asymptotic positive key rates over 175 km of telecom fibre. We show that the commonly used finite-key analysis for non-decoy state QKD drastically overestimates secure key acquisition times due to overly loose bounds on statistical fluctuations. Using the tighter multiplicative Chernoff bound to constrain the estimated finite key parameters, we reduce the required number of received signals by a factor 10 8 . The resulting finite key rate approaches the asymptotic limit at all achievable distances in acquisition times of one hour, and at 100 km we generate finite keys at 13 kbps for one minute of acquisition. This result is an important step towards long-distance single-emitter quantum networking.
Publisher: WORLD SCIENTIFIC
Date: 10-2005
Publisher: American Physical Society (APS)
Date: 26-08-2009
Publisher: SPIE
Date: 26-10-2016
DOI: 10.1117/12.2241491
Publisher: American Physical Society (APS)
Date: 07-08-2003
Publisher: American Physical Society (APS)
Date: 14-06-2005
Publisher: IOP Publishing
Date: 21-05-2014
Location: Australia
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Daniel Oi.