1 research outputs found
Improved Quantum LDPC Decoding Strategies For The Misidentified Quantum Depolarizing Channel
Quantum cryptography via key distribution mechanisms that utilize quantum
entanglement between sender-receiver pairs will form the basis of future
large-scale quantum networks. A key engineering challenge in such networks will
be the ability to correct for decoherence effects in the distributed
entanglement resources. It is widely believed that sophisticated quantum error
correction codes, such as quantum low-density parity-check (LDPC) codes, will
be pivotal in such a role. However, recently the importance of the channel
mismatch effect in degrading the performance of deployed quantum LDPC codes has
been pointed out. In this work we help remedy this situation by proposing new
quantum LDPC decoding strategies that can significantly reduce performance
degradation by as much as . Our new strategies for the quantum LDPC
decoder are based on previous insights from classical LDPC decoders in
mismatched channels, where an asymmetry in performance is known as a function
of the estimated channel noise. We show how similar asymmetries carry over to
the quantum depolarizing channel, and how an estimate of the depolarization
flip parameter weighted to larger values leads to significant performance
improvement.Comment: arXiv admin note: substantial text overlap with arXiv:arXiv:1202.035