Exploiting Degeneracy in Belief Propagation Decoding of Quantum Codes

Understand

Quantum information needs to be protected by quantum error-correcting codes due to imperfect physical devices and operations.

• One would like to have an efficient and high-performance decoding procedure for the class of quantum stabilizer codes.
• A potential candidate is Pearl's belief propagation (BP), but its performance suffers from the many short cycles inherent in a quantum stabilizer code, especially highly-degenerate codes.
• A general impression exists that BP is not effective for topological codes.