Fig. 3: Parallel window decoding schematic for 2D decoding problem, for example representing the repetition code with phenomenological noise.
From: Parallel window decoding enables scalable fault tolerant quantum computation
The decoding proceeds in two layers. In layer A, a number of non-overlapping windows An is decoded in parallel. The high confidence corrections in the middle ncom rounds of each window are committed to, while the corrections in the surrounding nbuf. The artificial defects are passed on to layer B. Windows Bn in layer B are fully committed to, resolving all the defects between the committed regions of layer A and completing the correction. All numerics are performed using a generalisation of this method to the 3D decoding problem representing the surface code with circuit-level noise.
