Design of nanophotonic circuits for autonomous subsystem quantum error   correction
  We reapply our approach to designing nanophotonic quantum memories to formulate an optical network that autonomously protects a single logical qubit against arbitrary single-qubit errors. Emulating the 9 qubit Bacon-Shor subsystem code, the network replaces the traditionally discrete syndrome measurement and correction steps by continuous, time-independent optical interactions and coherent feedback of unitarily processed optical fields. 
Joseph Kerckhoff, Dmitri S. Pavlichin, Hamidreza Chalabi and Hideo   Mabuchi
quant-ph physics.optics