Block-Layered Sign-Flipping Belief Propagation Decoder Architecture for Surface Codes

Quantum computing requires an error correction code to protect the messages against quantum noise. Surface codes are suitable for quantum error correction based on their local-qubit connection. Decoding via the conventional belief propagation (BP) algorithm is deficient for highly degenerated codes. Using the proposed block-layered sign-flipping (SF) technique, this problem can be mitigated and the error rate performance can be improved. The decoder hardware implemented for the [181, 1, 10] surface code occupies an area of 0.97 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>and achieves a latency of 315 ns in a 90 nm process.