Syndrome extraction for quantum LDPC codes in silicon: Distributed entanglement and mobile ancillas

arXiv:2611.13371v1 Announce Type: new Abstract: Quantum low-density parity-check (qLDPC) codes can reduce the number of data qubits required per logical qubit, but their checks require long-range interactions on a planar device. We develop a singlet fabric for bivariate-bicycle codes on a silicon node network. Spin singlets are generated on shuttling lanes and distributed between nodes, where local operations consume them to measure non-local stabilizers. We construct two syndrome-extraction circuits, based on distributed GHZ states and ancilla teleportation, and evaluate them using hardware-constrained schedules and circuit-level memory simulations. We compare these circuits with CAbLECAR, which transports a mobile ancilla between the data qubits of each check.