Quantum error detection in qubit-resonator star architecture
Abstract
Achieving industrial quantum advantage is unlikely without the use of quantum error correction (QEC). Other QEC codes beyond surface code are being experimentally studied, such as color codes and quantum Low-Density Parity Check (qLDPC) codes, that could benefit from new quantum processing unit (QPU) architectures. We introduce the six-qubit star lattice architecture that offers parallelism and effective local all-to-all connectivity and thus enables hardware-efficient implementation of certain QEC codes. As a first demonstration of this new architecture, we encode two logical qubits in a six-qubit superconducting QPU with a star-topology using the [[4, 2, 2]] code and characterize the logical states with the classical shadow framework. Logical life-time and logical error rate are measured over repeated quantum error detection cycles for various logical states including a logical Bell state. We measure logical state fidelities above 96 % for every cardinal logical state, find logical life-times above the best physical element, and logical error-per-cycle values ranging from 0.25(2) % to 0.91(3) %. In future, such star QPU can be tiled to enable QEC codes with high-weight and overlapping stabilizers for improved encoding rates.
Cite
@article{arxiv.2503.12869,
title = {Quantum error detection in qubit-resonator star architecture},
author = {Florian Vigneau and Sourav Majumder and Aniket Rath and Pedro Parrado-Rodríguez and Francisco Revson Fernandes Pereira and Hsiang-Sheng Ku and Fedor Simkovic and Stefan Pogorzalek and Tyler Jones and Nicola Wurz and Michael Renger and Jeroen Verjauw and Ping Yang and Hsiang-Sheng Ku and William Kindel and Frank Deppe and Johannes Heinsoo},
journal= {arXiv preprint arXiv:2503.12869},
year = {2025}
}