Constant-Overhead Fault-Tolerant Bell-Pair Distillation using High-Rate Codes

J. Pablo Bonilla Ataides, Hengyun Zhou, Qian Xu, Gefen Baranes, Bikun Li, Mikhail D. Lukin, Liang Jiang (Feb 14 2025).

Abstract: We present a fault-tolerant Bell-pair distillation scheme achieving constant overhead through high-rate quantum low-density parity-check (qLDPC) codes. Our approach maintains a constant distillation rate equal to the code rate - as high as $1/3$ in our implementations - while requiring no additional overhead beyond the physical qubits of the code. Full circuit-level analysis demonstrates fault-tolerance for input Bell pair infidelities below a threshold $\sim 5\%$, readily achievable with near-term capabilities. Unlike previous proposals, our scheme keeps the output Bell pairs encoded in qLDPC codes at each node, eliminating decoding overhead and enabling direct use in distributed quantum applications through recent advances in qLDPC computation. These results establish qLDPC-based distillation as a practical route toward resource-efficient quantum networks and distributed quantum computing.

Arxiv: https://arxiv.org/abs/2502.09542