BAQIS Quantum Science Forum 85: Scalable surface code decoders with parallelization in time



Date and Time:  17-March-2023  10:00am

Speaker:  Dr. Rui Chao, Alibaba Quantum Lab

Host: Dong Liu (Tsinghua University,BAQIS)

Title:  Scalable surface code decoders with parallelization in time


Abstract: Fast classical processing is essential for most quantum fault-tolerance architectures. We introduce a sliding-window decoding scheme that provides fast classical processing for the surface code through parallelism. Our scheme divides the syndromes in spacetime into overlapping windows along the time direction, which can be decoded in parallel with any inner decoder. With this parallelism, our scheme can solve the backlog problem as the code scales up, even if the inner decoder is slow. When using minimum-weight perfect matching and union-find as the inner decoders, we observe circuit-level thresholds of 0.68% and 0.55%, respectively, which are almost identical to those for the batch decoding. []


About the Speaker:

Rui Chao is a research scientist in Alibaba Quantum Lab. His interest is in quantum fault tolerance and error correction. Before joining Alibaba, he was a postdoc at Duke University under Prof. Ken Brown. He did PhD in Electrical Engineering under Prof. Ben Reichardt in University of Southern California. He obtained B.Eng in Computer Science in Tsinghua University.