Quantum error detection with star architecture QPU

The architecture of a QPU affects the performance of quantum error correction. The Star-configuration offers higher connectivity than the square-grid topology and thus enables more hardware efficient implementation of some error correction codes. We demonstrate error detection using a four-qubit code on a star-topology QPU. Our QPU features six superconducting transmon qubits coupled to a central resonator via tunable couplers. We apply two-qubit gates between pairs via the central resonator with a specific protocol based on qubit-resonator interaction. On this hardware, we characterize the lifetime, coherence time, and perform state tomography of the logical states.