Efficient Circuit Cutting and Scheduling in a Multi-Node Quantum System with Dynamic EPR Pairs

TL;DR

The paper tackles the challenge of executing large quantum circuits on noisy, resource-limited hardware by introducing EC2S, a framework that combines circuit cutting with dynamic, noise-aware EPR pairing in a multi-node quantum system. EC2S identifies optimal subcircuit cuts, selects worker pairs for physical EPR connections, and schedules subcircuits to minimize system expenditure while considering depolarizing noise and EPR imperfections. Through implementation in IBM Qiskit and Quantinuum Pytket and evaluation on real hardware and emulators, EC2S achieves up to 16.7% fidelity improvements and up to 99.5% reductions in SEME compared to the state-of-the-art Qiskit-Addon-Cut, illustrating practical benefits for scalable quantum computation. This work provides a concrete, hardware-aware pathway to reduce reconstruction overhead and enhance fidelity in distributed quantum systems, enabling more complex algorithms to run on near-term devices.

Abstract

Despite advancements, current quantum hardware faces significant challenges, including limited qubit counts and high susceptibility to noise, which hinder the execution of large, complex algorithms. To address these limitations, multi-node quantum systems and quantum circuit cutting techniques partition large circuits into smaller subcircuits that can be executed on individual quantum machines and then reconstructed using classical resources. However, these methods introduce new challenges, such as the large overhead from subcircuit reconstruction and additional noise from entangled EPR pairs, especially in multi-node quantum systems. In this paper, we propose the Efficient Circuit Cutting and Scheduling (EC2S) system, which integrates EPR pairs with circuit cutting to address these issues. EC2S improves system performance by transitioning from logical to physical EPR pairs and further reduces computational overhead by minimizing the number of subcircuits during the reconstruction phase. \sol~ is implemented using Qiskit and evaluated on both real quantum hardware and various emulators. Compared to the state-of-the-art Qiskit-Addon-Cut, EC2S achieves significant improvements in fidelity, up to 16.7\%, and reduces system-wide expenditure by up to 99.5\%.

Figures (9)

• Figure 1: A circuit cutting and reconstruction pipeline.
• Figure 2: A Circuit Cutting Example in a 3-node quantum system connected with two EPR Pairs
• Figure 3: A 4-node system with 2 EPR Pairs
• Figure 4: EC2S System Overview
• Figure 5: Fidelity Results in a Single-Node Environment