P2: Error-Aware Compilation of Quantum Circuits for the Rydberg Atom Platform (ECQuRyd)

Members: Prof. Dr. Hans Peter Büchler, Prof. Dr. Ilia Polian, Dr. Sebastian Weber

To execute a quantum algorithm on a hardware platform, it must be compiled to its native operations. This project aims at bridging the gap between recent technological advances in the Rydberg atom platform and its capability as a computational fabric for executing quantum circuits. This platform is very promising for scalable quantum computing, providing arrays of thousands of qubits, competitive gate fidelities, and a rich set of native operations not found in other platforms, such as various multi-qubit gates and dynamic changes of qubit connectivity by physically moving the qubits. Existing compilation approaches tend to focus on superconducting qubits and lack support for the extended features of the Rydberg atom platform. The project will bring together two research groups from Computer Science, bringing in competence in quantum circuit compilation and EDA; and Physics, contributing in-depth knowledge of the platform, its operations, error mechanisms and suppression, including an early-career researcher and first-time applicant.

Based on our seminal joint paper in the ICCAD conference 2021, we will develop compilation methods that fully utilize the considered platform's unique technological opportunities. Our methods will leverage detailed understanding of underlying error mechanisms and carefully employ techniques to overcome errors. Specifically, we will develop compilation methods that can use the entire variety of gates, including three-qubit gates on the Rydberg lattice, and shifts of Rydberg atoms in more than one direction to establish connectivity between initially distant physical qubits. In addition to features that have been experimentally demonstrated, we will consider possible future improvements of the platform, thus providing valuable input for experimental physicists about the expected practical relevance of these improvements.

As a key distinction of our approach, we will establish an understanding of error mechanisms in Rydberg atoms and means to overcome them, and investigate the intricate relationship between error-aware operation and compilation. A central technique employed here will be microscopic simulations, yielding compact and yet detailed error models based on Kraus representation. Incorporating them into compilation methods for larger circuits requires intensive cross-disciplinary interaction and goes far beyond today’s consideration of errors during compilation. Here, the Computer Science partners contribute their extensive experience in quantum circuit compilation on Rydberg atom and on other platforms, whereas the Physics partners provide their in-depth knowledge of the Rydberg atom platform, its properties and error mechanisms. The project is positioned in the SPP's RA 3, as its focal points are platform-specific and technology-aware compilation techniques. It is also strongly connected to RA4 and specifically the EDA methods for quantum hardware.