modular quantum networks

Clayton Crocker, I. V. Inlek, David Hucul +3 more

Markku Hahto, Jyrki Piilo, Johannes Nokkala

Abstract Quantum state transfer is the act of transferring quantum information from one system in a quantum network to another without physically transporting carriers of quantum information, but instead engineering a Hamiltonian such that the state of the sender is transferred to the receiver through the dynamics of the whole network. A generalization of quantum state transfer called quantum routing concerns simultaneous transfers between multiple pairs in a quantum network, imposing limitations on its structure. This study considers transfer of Gaussian states over noisy quantum networks with modular structure, which have been identified as a suitable platform for quantum routing. Two noise models are compared, affecting either the network topology or the network constituents, studying their effects on both the transfer fidelities and the network properties. The two models are found to affect different features of the network allowing for the identification and quantification of the noise. These features are then used as a guide toward different strategies for the compensation of the noise, and to examine how the compensation strategies perform. The results show that in general, modular networks are more robust to noise than monolithic ones.

Günter Mahler A, Volker A. Weberruß

Jincheng Zhang

Quantum field networks (QFNs) represent a promising avenue for quantum information processing, offering potential advantages over traditional qubit-based systems. However, the inherent complexity of managing and manipulating quantum fields presents a significant challenge. This paper introduces the concept of Modular Quantum Field Networks (MQFNs), a novel framework designed to address this challenge through the construction of interconnected, programmable quantum components. MQFNs leverage a system for assembling, combining, and re-configuring smaller, independent units, enabling rapid reconfiguration of quantum systems. We propose a methodology for creating and updating these units, focusing on the inherent modularity and programmability of the network. The design aims to create robust, scalable, and adaptable quantum systems, addressing key limitations of current QFN architectures. This work will explore the architectural implications of MQFNs and their potential to facilitate the development of complex quantum computations and distributed quantum sensing.

Günter Mahler A, Volker A. Weberruß

Tianjie Hu, Jindi Wu, Qun Li

Quantum networks encounter unavoidable channel noises and erasure errors, presenting a huge obstacle in designing protocols that attain both high reliability and efficiency. Typically, quantum networks fall into two categories: those utilize quantum entanglements for quantum teleportation, and those directly transfer the actual quantum messages. In this paper, we present SurfNet, a quantum network that inherits the main advantages from both categories. It employs surface codes as logical qubits for encoding messages, and utilizes two parallel communication channels to fault-tolerantly transfer each surface code in a modular manner. Our approach of using surface codes can timely correct both operational and photon loss errors within the network, and the integration of the two channels within the network can greatly improve network throughput. For the implementation of SurfNet, we propose a novel network architecture, designed to better integrate surface codes into quantum networks. We also propose a novel error correction decoder, designed to fully utilize the modular characteristic of surface codes within our network. Simulation results demonstrate that SurfNet with its decoder significantly enhances the communication fidelity within quantum networks.