CUNQA
Emulator of Distributed Quantum Computing for HPC environments
Documentation
CUNQA is a Python/C++ platform that emulates distributed quantum computing (DQC) architectures on HPC environments. To achieve this, CUNQA defines the concept of a virtual QPU (vQPU), which is a combination of classical resources and simulation software that, working together, simulate the appearance and operation of a real QPU. These vQPUs are responsible for executing the quantum tasks defined by the user.
For these vQPUs to work, they require a management system. This system is written in C++, aiming for higher performance and better integration with the simulation libraries, most of which are also written in this language. In addition to this management system, it was necessary to define an API that allows the definition of quantum tasks and their subsequent submission to the vQPUs, providing an intuitive and convenient way of using the platform. The API was implemented in Python, as it offers a more accessible and user-friendly entry point.
This documentation will exclusively detail the parts of the library that are required by the user to employ the platform which can be found in the CUNQA reference section.
All the code is available on the GitHub repository and a detailed explanation of the work done can be seen at the CUNQA preprint [vazquez2025].
This work has been mainly funded by the project QuantumSpain, financed by the Ministerio de Transformación Digital y Función Pública of Spain's Government through the project call QUANTUM ENIA - Quantum Spain project, and by the European Union through the Plan de Recuperación, Transformación y Resiliencia - NextGenerationEU within the framework of the Agenda España Digital. 1. J. Vázquez-Pérez was supported by the Axencia Galega de Innovación (Xunta de Galicia) through the Programa de axudas á etapa predoutoral (ED481A & IN606A). Additionally, this research project was made possible through the access granted by the Galician Supercomputing Center (CESGA) to two key parts of its infrastructure. Firstly, its Qmio quantum computing infrastructure with funding from the European Union, through the Operational Programme Galicia 2014-2020 of ERDF_REACT EU, as part of the European Union's response to the COVID-19 pandemic. Secondly, The supercomputer FinisTerrae III and its permanent data storage system, which have been funded by the NextGeneration EU 2021 Recovery, Transformation and Resilience Plan, ICT2021-006904, and also from the Pluriregional Operational Programme of Spain 2014-2020 of the European Regional Development Fund (ERDF), ICTS-2019-02-CESGA3, and from the State Programme for the Promotion of Scientific and Technical Research of Excellence of the State Plan for Scientific and Technical Research and Innovation 2013-2016 State subprogramme for scientific and technical infrastructures and equipment of ERDF, CESG15-DE-3114.
J. Vázquez-Pérez, D. Expósito-Patiño, M. Losada, Á. Carballido, A. Gómez y T. F. Pena, CUNQA: a Distributed Quantum Computing emulator for HPC, arXiv:2511.05209 [quant-ph], 2025. Available at: https://arxiv.org/abs/2511.05209