We construct two simple error correction schemes adapted to amplitude damping noise for Bacon-Shor codes and investigate their prospects for fault-tolerant implementation. Both consist solely of Clifford gates and require far fewer qubits, relative to the standard method, to achieve exact correction to a desired order in the damping rate. The first, employing one-bit teleportation and single-qubit measurements, needs only one-fourth as many physical qubits, while the second, using just stabilizer measurements and Pauli corrections, needs only half. The improvements stem from the fact that damping events need only be detected, not corrected, and that effective phase errors arising due to undamped qubits occur at a lower rate than damping errors. For error correction that is itself subject to damping noise, we show that existing fault-tolerance methods can be employed for the latter scheme, while the former can be made to avoid potential catastrophic errors and can easily cope with damping faults in ancilla qubits.

Physical Review Letters
Centrum Wiskunde & Informatica, Amsterdam (CWI), The Netherlands

Piedrafita Postigo, Á., & Renes, J. (2017). Reliable channel-adapted error correction: Bacon-Shor code recovery from amplitude damping. Physical Review Letters, 119(25), 250501:1–250501:8. doi:10.1103/PhysRevLett.119.250501