A Framework for Quantum Data Center Emulation Using Digital Quantum Computers

Abstract: As quantum computing hardware advances, the limitations of single-chip architectures, particularly in terms of small qubit count, have sparked growing interest in modular quantum computing systems and Quantum Data Centers (QDCs). These architectures interconnect multiple quantum processor units (QPUs) to overcome physical constraints and support complex quantum algorithms. However, the implementation of distributed quantum computing (DQC) faces significant technical challenges, especially in the execution of remote gates. Moreover, no practical emulation tool currently exists to evaluate theoretical proposals of various DQC systems. In this work, we propose a framework that emulates a DQC system using a single quantum processor. We partition the physical qubit coupling map of an existing QPU into multiple logical QPUs, and introduce an experimentally grounded noise model based on quantum collision dynamics to quantify the interconnect-induced noise, representing fiber-connected QPUs. The framework is validated using IBM's quantum hardware, demonstrating the successful execution of remote gates under noisy conditions. Furthermore, we implement distributed versions of Grover's search and the Quantum Fourier Transform (QFT), showing that complex circuits can be executed within the proposed framework with reasonable fidelity across interconnected QPUs. The emulation result of Grover's algorithm aligns with the real-world experimental implementations between two Ion-trapped QPUs interconnected by optical fiber, which demonstrate the feasibility and accuracy of our framework. Overall, this work provides a versatile emulation tool for investigating QDC behavior while accounting for interconnect-induced communication noise and offers a practical method for validating distributed quantum protocols without requiring specialized interconnect hardware.