Noise-aware Quantum Programming (NawaQ)

• Applicants: Professor Dr. Benjamin Lucien Kaminski; Dr. Tobias Stollenwerk
• Subject Area: Software Engineering and Programming Languages
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 563038229

Quantum computing holds the promise of delivering significant advantages over classical computing for hard computational problems. However, the inherent fragility of quantum information, despite its power, poses a critical challenge: Real quantum hardware is unavoidably noisy, hence unreliable, necessitating the development of countermeasures to manage this noise. These challenges span both near-term Noisy Intermediate-Scale Quantum (NISQ) computation - characterized by its noise-robustness but also by its limited capabilities - as well as long-term fault-tolerant quantum computation, which relies on quantum error correction. In both paradigms, low-level quantum software must be aware of and address the pervasive effects of quantum noise, ensuring reliable operation. In a nutshell, the NawaQ project seeks to make quantum programming noise-aware. Specifically, we want to create theoretical tools and frameworks that integrate noise awareness into both low-level quantum circuits and higher-level quantum programming languages, ensuring reliability and efficiency of quantum algorithms in the face of inevitable hardware imperfections. At the lower level, quantum circuits form the basic building blocks of quantum computation. Quantum programs written in a high-level language are compiled to quantum circuits which can then be executed on real hardware. Noise-aware compilation is a rapidly advancing field that aims to integrate device-specific information into the compilation process. However, significant challenges remain: For one, the nature of quantum noise channels is difficult to characterize accurately on real quantum hardware. Furthermore, understanding the impact of these noise channels on quantum algorithm performance is challenging. This makes it hard to guarantee reliable execution on real quantum hardware. To address these challenges, we aim to integrate detailed noise information (device-specific or more general) into quantum circuits and their representations (e.g. ZX-diagrams). Thereby, we want to establish a formal framework for the quantitative analysis of noisy quantum circuits. Such a framework could serve as the basis for more sophisticated noise-aware circuit compilation techniques. At the higher level, quantum programming languages are as of today, bluntly stated, noise-unaware. However, a programmer being able to explicitly query for quantum noise information and steering the program’s control flow accordingly may enable innovative algorithm designs, expand the scope of quantum applications, and unlock new computational possibilities. We hence aim to extend noise-awareness also to the programming language level. We will design a quantum programming language that supports noise queries, allowing programmers to interact with and account for noise at source code level. We will provide a formal semantics and develop a program logic, which will in turn allow for formal reasoning about the correctness of noise-aware quantum programs.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2514: Quantum Software, Algorithms and Systems - Concepts, Methods and Tools for the Quantum Software Stack
• International Connection: Japan
• Co-Investigators: Dr. Alessandro Ciani; Professor Dr. Frank K. Wilhelm-Mauch
• Cooperation Partner: Professor Dr. Ichiro Hasuo