HIPERCOM
Lead Research Organisation:
University of York
Department Name: Computer Science
Abstract
Coherent optics has been known since the 1960's to be, in principle, the best tool to achieve very high bandwidths and bit rates in optical communication. While the development of fiber optical amplifiers in the 1980's has reduced the need for developing such a technology, the advent of quantum information sciences has triggered a renewed interest in using coherent optics to realize high-rate quantum communication systems. The present project is focused on coherent quantum communication as a way to combine the intrinsically very high rates achievable by homodyne or heterodyne detection with the fundamental benefits of using quantum mechanics such as unconditional security.
Unlike with classical communication systems, an optical amplifier cannot be used as a repeater in a quantum communication setup because it is inherently limited by quantum noise. The thrust of this project is to explore different techniques aiming at circumventing this problem and improving the range of coherent (also called continuous-variable) quantum communication systems, with a special emphasis on today's most developed platform towards practical applications, namely continuous-variable quantum key distribution. Different strategies will be followed in order to attain this goal, ranging from the use of classical coding and other post-processing algorithms, which is the most directly applicable solution in the short term, to more elaborate longer-term techniques relying on specific quantum optical schemes and ultimately on the use of quantum coding. In particular, the potential solutions offered by the heralded noiseless linear amplifier, or other non-Gaussian heralded operations, will be investigated in detail.
The specificity of our consortium is to combine the strength of 5 academic groups having an outstanding track record in the area of coherent (continuous-variable) quantum information science, including 2 theory (Universite Libre de Bruxelles, University of York) and 3 experimental (Institut d'Optique Graduate School, Max Planck Institute for the Science of Light, Telecom Paris Tech) groups, together with 1 industrial partner (SeQureNet) who will naturally orient the research towards the needs of the information society. We envision that this synergy between applied and fundamental - both theoretical and experimental - teams will be highly stimulating and productive, and will reinforce European competitiveness in information technologies.
Unlike with classical communication systems, an optical amplifier cannot be used as a repeater in a quantum communication setup because it is inherently limited by quantum noise. The thrust of this project is to explore different techniques aiming at circumventing this problem and improving the range of coherent (also called continuous-variable) quantum communication systems, with a special emphasis on today's most developed platform towards practical applications, namely continuous-variable quantum key distribution. Different strategies will be followed in order to attain this goal, ranging from the use of classical coding and other post-processing algorithms, which is the most directly applicable solution in the short term, to more elaborate longer-term techniques relying on specific quantum optical schemes and ultimately on the use of quantum coding. In particular, the potential solutions offered by the heralded noiseless linear amplifier, or other non-Gaussian heralded operations, will be investigated in detail.
The specificity of our consortium is to combine the strength of 5 academic groups having an outstanding track record in the area of coherent (continuous-variable) quantum information science, including 2 theory (Universite Libre de Bruxelles, University of York) and 3 experimental (Institut d'Optique Graduate School, Max Planck Institute for the Science of Light, Telecom Paris Tech) groups, together with 1 industrial partner (SeQureNet) who will naturally orient the research towards the needs of the information society. We envision that this synergy between applied and fundamental - both theoretical and experimental - teams will be highly stimulating and productive, and will reinforce European competitiveness in information technologies.
Planned Impact
Not relevant
Organisations
Publications
Abdi M
(2014)
Continuous-variable-entanglement swapping and its local certification: Entangling distant mechanical modes
in Physical Review A
Abdi M
(2012)
Entanglement swapping with local certification: application to remote micromechanical resonators.
in Physical review letters
Barzanjeh S
(2013)
Continuous-variable dense coding by optomechanical cavities
in Physical Review A
Barzanjeh S
(2015)
Microwave quantum illumination.
in Physical review letters
Braunstein SL
(2012)
Side-channel-free quantum key distribution.
in Physical review letters
Elemans M
(2014)
Rates of CTL killing in persistent viral infection in vivo.
in PLoS computational biology
Lupo C
(2012)
Capacities of linear quantum optical systems
in Physical Review A
Lupo C
(2013)
Quantum reading capacity under thermal and correlated noise
in Physical Review A
Nair R
(2012)
Symmetric M -ary phase discrimination using quantum-optical probe states
in Physical Review A
Ottaviani C
(2015)
Continuous-variable quantum cryptography with an untrusted relay: Detailed security analysis of the symmetric configuration
in Physical Review A
| Description | 1) Extension of QKD to thermal states and infrared regime, for potential application to wireless networks. This has been done both for standard one-way and more powerful two-way protocols. Now new devices such as PC/phone infrared port or microwave connections can potentially be used for QKD at short distances. 2) Proof of quantum discord as a fundamental resource for QKD, clarifying its role in device-dependent QKD, including the new field of measurement-device-independent QKD, for which the presence of entanglement is no longer necessary 3) Development of measurement-device independent QKD for potential applications to network topologies involving untrusted relays and fulfilling the end-to-end principle. This has created a new field of investigation and represents the first step towards a secure metropolitan network, where devices are forced to connect to untrusted public hot spots in order to communicate with each other. Recently we have also extended this idea to continuous variable systems, both theoretical and experimentally. This work has proven that continuous variable QKD can be secure in an arbitrary Gaussian environment where the eavesdropper is allowed to use arbitrary quantum-correlations to probe the transmitted signals, and can even tamper with the working mechanism of the middle relay used by Alice and Bob for connecting. From this point of view, we have fully reached our milestone result within the HIPERCOM project. 4) Proof of the connection between the bosonic minimum output entropy and Gaussian discord, with full clarification of the nature of quantum correlations for a wide family of Gaussian states. This finding is important not only in QKD but also in other protocols of quantum technology where the preparation of well-tailored quantum correlated sources is fundamental. 5) Entanglement distribution on non-Markovian environments. We have shown that the distribution of entanglement (which is a sufficient but not necessary condition for a secure QKD) can be reactivated even in the presence of entanglement-breaking channels, as long as residual memory effects can be found in the environment. 6) We have also proven that the distribution of entanglement via the technique of entanglement swapping can be easily certified. This technique is particularly useful for opto-mechanical systems and cavities. For these systems we have also studied the protocol of dense coding. 7) Finally, we have also found other results of interest for the quantum information community, such as general formulas for computing the covariance matrix of bosonic systems subject to Bell-like detections, the ultimate capacity of linear quantum optical systems, and the optimal symmetric M-ary discrimination of coherent states. |
| Exploitation Route | Our paper on side-channel-free quantum key distribution (QKD) has contributed to created a completely new field in quantum cryptography, known as measurement-device-independent QKD, with many theoretical studies and several experimental realizations. Our idea has allowed many researchers working in QKD to extend the security distances of their protocols and achieve higher key rates. Most importantly, our paper has proved that QKD can be secure even in the presence of untrusted relays, therefore proving the first step towards the realization of a realistic end-to-end secure quantum network. To date (23 October 2014) our 2012-paper has been already cited 78 times according to Google Scholar. The field of measurement-device-independent QKD is today one of the most important advance in quantum cryptography, with other new studies and advances. In particular, the experimental realizations are already quite advanced and incoming technological implementations are expected in the future. |
| Sectors | Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Education,Security and Diplomacy |
| Description | Our paper on side-channel-free quantum key distribution (QKD) has contributed to created a completely new field in quantum cryptography, known as measurement-device-independent QKD, with many theoretical studies and several experimental realizations. Our idea has allowed many researchers working in QKD to extend the security distances of their protocols and achieve higher key rates. Most importantly, our paper has proved that QKD can be secure even in the presence of untrusted relays, therefore proving the first step towards the realization of a realistic end-to-end secure quantum network. To date (23 October 2014) our 2012-paper has been already cited 78 times according to Google Scholar. The field of measurement-device-independent QKD is today one of the most important advance in quantum cryptography, with other new studies and advances. In particular, the experimental realizations are already quite advanced and incoming technological implementations are expected in the future. |
| First Year Of Impact | 2014 |
| Sector | Digital/Communication/Information Technologies (including Software),Education,Security and Diplomacy |
| Impact Types | Cultural,Societal |