On Global Quantum Communication Networking

Abstract

Research in quantum communications networks (QCNs), where multiple users desire to generate or transmit common quantum-secured information, is still in its beginning stage. To solve for the problems of both discrete variable- and continuous variable-quantum key distribution (QKD) schemes in a simultaneous manner as well as to enable the next generation of quantum communication networking, in this Special Issue paper we describe a scenario where disconnected terrestrial QCNs are coupled through low Earth orbit (LEO) satellite quantum network forming heterogeneous satellite–terrestrial QCN. The proposed heterogeneous QCN is based on the cluster state approach and can be used for numerous applications, including: (i) to teleport arbitrary quantum states between any two nodes in the QCN; (ii) to enable the next generation of cyber security systems; (iii) to enable distributed quantum computing; and (iv) to enable the next generation of quantum sensing networks. The proposed QCNs will be robust against various channel impairments over heterogeneous links. Moreover, the proposed QCNs will provide an unprecedented security level for 5G+/6G wireless networks, Internet of Things (IoT), optical networks, and autonomous vehicles, to mention a few.

Hybrid CV-DV Quantum Communications and Quantum Networks

“…An alternative solution leveraged satellites as relays for QuCom over thousands of kilometers by virtue of the more favorable quadratic scaling of photon loss versus the distance in free-space optical (FSO) links. Remarkably, quantum key distribution [5], quantum teleportation [6], and entanglement distribution [7] were demonstrated in a ground-to-satellite QuCom testbed across several-thousand kilometers, showing tremendous potential to build up a satellite-mediated widearea quantum communication network (QCN) via FSO links, in similar fashion as we proposed in [8]. At present, while QuComs are individually validated over specific types of quantum point-to-point links, the QCN that enables full integration of diverse QIP devices into a unified network must still be developed.…”

“…The cluster state-based quantum networking concept was introduced in our previous paper [8]. When the cluster C is defined as a connected subset on a d-dimensional lattice, it obeys the set of eigenvalue equations S a | C =| C , where S a =X a  bN(a) Z b are stabilizer operators with N(a) denoting the neighborhood of a∈C.…”

“…When the cluster C is defined as a connected subset on a d-dimensional lattice, it obeys the set of eigenvalue equations S a | C =| C , where S a =X a  bN(a) Z b are stabilizer operators with N(a) denoting the neighborhood of a∈C. To create a 2-D cluster state, the approach proposed by Gilbert et al [23] was employed in [8]. This utilizes linear states (generated by spontaneous PDC, local unitaries, and type I fusion) to create the desired 2-D cluster state.…”

“…To establish EPR pairs between any two nodes we need to perform properly selected Y and Z measurements as described in ref. [8]. If we are not interested in distributed quantum computing or sensing but just in quantum networking the cluster state concept is not really needed because we can create arbitrary quantum network topology by performing the delocalized photon additions on properly chosen nodes in the network.…”

QKD-Enhanced Cybersecurity Protocols

“…To extend transmission distance further, we can use the adaptive optics approaches [5]. By placing the location of Charlie on LEO satellite distance between two quantum nodes can be significantly extended (see [19] for more details). This approach is applicable to both DV-QKD and CV-QKD schemes as demonstrated in [20].…”