Ubiquitous Quantum Communications

Project Information

QuantCom

Grant agreement ID: 789028

DOI

10.3030/789028

Project closed

EC signature date 23 May 2018

Start date 1 June 2018

End date 30 November 2024

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 2 496 372,00

EU contribution

€ 2 496 372,00

Coordinated by

UNIVERSITY OF SOUTHAMPTON
United Kingdom

Periodic Reporting for period 4 - QuantCom (Ubiquitous Quantum Communications)

Reporting period: 2022-12-01 to 2024-11-30

Summary of the context and overall objectives of the project

THE PROBLEM:
The holistic optimization of the overall QuantCom system relying on the space-air-ground integrated network (SAGIN) concept. This is vital for the development of seamless wireless coverage, integrating satellites, unmanned aerial vehicles (UAVs) and manned aircraft, along with the terrestrial infrastructure, to provide resilient ubiquitous communications.

IMPORTANCE TO SOCIETY:
In recent years many high-profile international eavesdropping events have been reported in the media. Some of these created global political hostility amongst nations, others inflicted substantial fiscal losses or divulged private banking as well as health-related information. Hence the early introduction of ultimately secure QKD solutions is of salient importance. The most advanced version of these systems is constituted by the above-mentioned SAGIN concept, which would support users on the move.

THE OBJECTIVES:
1/ Design near-hashing-bound near-unity-rate quantum codes.
2/ Decide whether to use so-called forward-oriented direct-reconciliation or backwards-oriented reverse-reconciliation schemes.
3/ Determine the most potent error correction codes to be used for both direct-reconciliation and for reverse-reconciliation.
4/ Conceive a suite of new QKD architectures.
5/ As for the design of SAGIN systems, one of the most critical design dilemmas is, how to circumvent the blockage of line-of-sight propagation between the source and destination. Hence the design of optical reflective intelligent surfaces (ORIS) has to be explored.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The results of the project have been disseminated in 506 journal papers, which can be found in green open access at
https://www.researchgate.net/profile/L-Hanzo?ev=hdr_xprf
https://scholar.google.co.uk/scholar?q=lajos+hanzo+eprint&hl=en&as_sdt=0&as_vis=1&oi=scholart
The citation impacts can be viewed at
https://scholar.google.co.uk/citations?user=p0jnEW0AAAAJ&hl=en
Some of the key results are highlighted here
https://www-mobile.ecs.soton.ac.uk/res/int/quantum

Furthermore, a 500-page research monograph was commissioned by the John Wiley and IEEE Press, which will be published in 2025 on quantum error correction codes for exploitation by the scientific community.
Additionally, numerous keynote lectures and webinars were presented at the prestigious flagship conferences of the IEEE, see for example
https://www.youtube.com/watch?v=81W3ollhpYk
https://www.comsoc.org/about/news/lajos-hanzo-instruct-introduction-quantum-communications-course-3-may
https://wtc.committees.comsoc.org/seminars/
https://rc.signalprocessingsociety.org/education/webinars/spsweb00373

The PI has also created a detailed quantum communications curriculum for the IEEE, which he is offering twice or thrice a year to the global community. This course has also been presented at many IEEE conferences. Finally, the PI founded the IEEE Communication Society’s Quantum Communications and Information Technology subcommittee, which has grown to 500+ members.
https://qcit.committees.comsoc.org/officers/

WP 1: QUANTUM DECOHERENCE MITIGATION AND QUANTUM CODES

A suite of quantum error correction codes (QECC) was designed for mitigating the decoherence and was disseminated in leading-edge IEEE journals, as seen in the list of publications. The most inventive solutions are our short topological block codes, which correct the errors before the decoherence results in catastrophic error-proliferation.
A compelling feature of the adaptive-rate short codes designed is that they lend themselves to reconfiguration as different-rate codes, which are eminently suitable for mitigating time-variant decoherence in the face of fluctuating environmental influence. This unique feature allows them to maintain a specific target integrity by appropriately adjusting the throughput attained.
Furthermore, the first ever so-called universal quantum decoders were invented, which may be harnessed for decoding arbitrary linear codes, such as Bose-Chaudhuri-Hocquenghem (BC) and Polar codes, for example. These schemes have also inspired new classical decoder designs by the PI and his team.
Finally, as a low-complexity design alternative, quantum error mitigation solutions dispensing with the employment of quantum codes have been conceived and disseminated.

WP 2: QUANTUM KEY DISTRIBUTION

A suite of new protocols was designed for both reverse reconciliation (RR) and direct reconciliation (DR). In the proposed RR scheme, the computational complexity is balanced between the transmitter (Alice) and receiver (Bob) by generating the secret key and the frozen bit-based side information at Bob's and Alice's sides, respectively. Consequently, Polar decoding is used by Alice, and LDPC decoding by Bob, instead of carrying out both decoding tasks at one side. We demonstrated that short Polar codes are capable of outperforming LDPC codes in CV-QKD reconciliation, when using block lengths below 512 bits.

WP 3: ENTANGLEMENT SWAPPING

QUANTUM TELEPORTATION is the key communication functionality of the Quantum Internet, allowing the "transmission'' of qubits without the physical transfer of the particle storing the qubit. Quantum teleportation is facilitated by the action of quantum entanglement, a somewhat counter-intuitive physical phenomenon with no direct counterpart in the classical world. As a consequence, the very concept of the classical communication system model has to be redesigned to account for the peculiarities of quantum teleportation. This re-design is a crucial prerequisite for constructing any effective quantum communication protocols. The aim of this WP is to shed light on this key concept, with the objective of highlighting the fundamental differences between the transmission of classical information versus the teleportation of quantum information. This allowed us to investigate quantum teleportation and to tackle some of the challenges in the design of practical quantum teleportation in the face of the ubiquitous quantum decoherence, which has no direct counterpart in the classical world.

WP 4: SPACE-AIR-GROUND INTEGRATED NETWORK (SAGIN)

The quantum-domain Space-Air-Ground Integrated Network (SAGIN) concept was developed and characterized.
Furthermore, we have discovered that Rydberg atoms exhibit compelling advantages in terms of detecting classical-domain radio frequency signals. Based on this, Rydberg atomic quantum receivers (RAQRs) were designed for classical wireless communication and sensing. To harness the advantages and exploit the potential of RAQRs in wireless sensing, we conceived powerful classical transceivers relying on RAQRs.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

QuantCom has advanced the SOTA in QKD, quantum-secured direct communications (QSDC), entanglement-processing and SAGIN systems, as documented in 506 IEEE journal papers and a research monograph.

The overall system concept of QuantCom