Shor code using a local, two-dimensional architecture. We embed the data qubits in a 7 by 7
array of physical qubits, where the extra qubits are used for ancilla preparation and qubit
transportation by means of a SWAP chain. The latency is reduced with respect to a similar
implementation using Steane's 7-qubit code (KM Svore, DP DiVincenzo, and BM Terhal,
Quantum Information & Computation {\bf 7}, 297 (2007)). Furthermore, the error threshold is …