Quantum network protocols

Matheus Guedes de Andrade, Jake Navas, Inès Montaño +1 more

The experimental realization of quantum information systems will be difficult due to how sensitive quantum information is to noise. Overcoming this sensitivity is central to designing quantum networks capable of transmitting quantum information reliably over large distances. Moreover, the ability to characterize communication noise in quantum networks is crucial in developing network protocols capable of overcoming the effects of noise in quantum networks. In this context, quantum network tomography refers to the characterization of channel noise in a quantum network through end-to-end measurements. In this work, we propose network tomography protocols for quantum star networks formed by quantum channels characterized by a single, non-trivial Pauli operator. Our results further the end-to-end characterization of quantum bit-flip star networks by introducing tomography protocols where state distribution and measurements are designed separately. We build upon previously defined quantum network tomography protocols, as well as provide novel methods for the unique characterization of bit-flip probabilities in stars. We introduce a theoretical benchmark based on the Quantum Fisher Information matrix to compare the efficiency of quantum network protocols. We apply our techniques to the protocols proposed, and perform an initial analysis on the potential benefits of entanglement for Quantum Network Tomography. Furthermore, we simulate the protocols using N etSquid to assess the convergence properties of the estimators obtained for particular parameter regimes. Our findings show that the efficiency of protocols depend on parameter values and motivate the search for adaptive quantum network tomography protocols.

Ming-Xing Luo

Laura DeNardis

Yuan Cao, Yongli Zhao, Jie Zhang +3 more

In the initial stage of the quantum Internet, most of the practical quantum networks have been deployed relying on diverse individual quantum key distribution (QKD) protocols. However, this single-protocol paradigm cannot fulfill the heterogeneous requirements of the users, hence market-penetration of quantum networks is limited. Given the recent advances in QKD protocols, the next generation quantum networks are expected to support both legacy and emerging QKD protocols. However, the evolution from single-protocol to multi-protocol quantum networks poses numerous challenging problems. As a remedy, we conceive a practical protocol translation framework for supporting this migration from single-protocol to large-scale multi-protocol quantum networks. Furthermore, we propose a programmable multi-functional relay node architecture for harmonizing the components of a suitable relay node. A pair of protocol translation policies are presented for meeting the challenging security requirements of migration requests, which are compared to the single-protocol-based migration solutions both in terms of the translation success probability attained (i.e., the proportion of migration requests with successful protocol translation), and the average relaying risk probability encountered (i.e., the mean of the relaying risk probabilities of end-to-end key negotiation in a quantum network). Finally, we highlight a suite of open problems in both quantum secure direct communication and quantum teleportation for research into future multi-protocol quantum networks.

Leonardo Bacciottini, Luciano Lenzini, Enzo Mingozzi +1 more

The Quantum Internet architecture and its associated functionality are far from being standardized. Furthermore, the protocol stack that implements the abovementioned functionality is still under development. In this work, we present a framework to DEsign and Synthesize Quantum netwoRk InteroperaBle protocols for Entanglement distribution (DeSQribe), a novel iteration of the Software-Defined Networking (SDN) paradigm. DeSQribe introduces a methodology to define and implement arbitrary entanglement distribution and distillation protocols. Distinct from adaptations of existing SDN solutions to quantum networks, DeSQribe tackles quantum-specific challenges, such as the dual nature of a data plane that accommodates classical messages and quantum states. DeSQribe defines a protocol as an ordered sequence of processing units that manipulate quantum states and exchange classical messages. This high modularity encourages software reusability. A centralized controller leverages DeSQribe and dynamically orchestrates protocols on network devices. Finally, DeSQribe's technology-agnostic nature assures seamless integration across diverse quantum technologies. We showcase how to implement and combine entanglement distribution protocols of very different natures (e.g., connectionless, connection-oriented) with DeSQribe, proving its flexibility and timeliness.

Peter P. Rohde