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arXiv:2502.11972 · IEEE International Symposium on Circuits and Systems proceedings

Waveguide QED Analysis of Quantum-Coherent Links for Modular Quantum Computing

Junaid Khan, Sergio Navarro Reyes, Sahar Ben Rached, Eduard Alarcón, P. Haring Bolívar, Carmen G. Almudéver, Sergi Abadal

Published May 25, 2025• 0 citations
arXivHTMLPDF

Abstract

Waveguides potentially offer an effective medium for interconnecting quantum processors within a modular framework, facilitating the coherent quantum state transfer between the qubits across separate chips. In this work, we analyze a quantum communication scenario where two qubits are connected to a shared waveguide, whose resonance frequency may match or not match that of the qubits. Both configurations are simulated from the perspective of quantum electrodynamics (QED) to assess the system behavior and key factors that influence reliable interchip communication. The primary performance metrics analyzed are quantum state transfer fidelity and latency, considering the impact of key system parameters such as the qubit-waveguide detuning, coupling strength, waveguide decay rate, and qubit decay rate. We present the system design requirements that yield enhanced state transmission fidelity rates and lowered latency, and discuss the scalability of waveguide-mediated interconnects considering various configurations of the system.

DOI
10.1109/iscas56072.2025.11043734

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Cavity-mediated interconnects are a promising platform for scaling modular quantum computers by enabling highfidelity inter-chip quantum state transmission and entanglement generation. In this work, we first model the dynamics of deterministic inter-chip quantum state transfer using the Stimulated Raman Adiabatic Passage (STIRAP) protocol, analyzing fidelity loss mechanisms under experimentally achievable qubitcavity coupling and decoherence parameters. We then extend the NetSquid simulator, typically used for simulating longrange quantum communication networks, to support cavity-based communication channels for mediating inter-chip state transfer and entanglement generation. We model cavities as amplitude damping channels parameterized by physical system characteristics; cavity decay rateκ\kappaκand qubit-cavity coupling strengthggg, and analyze the impact of intrinsic qubit decoherence factors dictated byT1T_{1}T1​andT2T_{2}T2​times. Our simulations accurately represent the system's dynamics in both strong and weak coupling regimes, and identify critical trade-offs between fidelity, latency, and noise factors. The proposed framework supports faithful modeling and scalable simulation of modular architectures, and provides insights into design optimization for practical quantum network implementations.