FPGA-based Distributed Union-Find Decoder for Surface Codes

Understand

A fault-tolerant quantum computer must decode and correct errors faster than they appear to prevent exponential slowdown due to error correction.

• The Union-Find (UF) decoder is promising with an average time complexity slightly higher than $O(d^3)$.
• We report a distributed version of the UF decoder that exploits parallel computing resources for further speedup.
• Using an FPGA-based implementation, we empirically show that this distributed UF decoder has a sublinear average time complexity with regard to $d$, given $O(d^3)$ parallel computing resources.