Tesseract: A Search-Based Decoder for Quantum Error Correction

Tesseract is a Most-Likely-Error decoder designed for quantum error-correcting codes. Tesseract conducts a search through an graph on the set of all subsets of errors to find the lowest cost subset of errors consistent with the input syndrome. Although this set is exponentially large, the search can be made efficient in practice for random errors using A* along with a variety of pruning heuristics. We show through benchmark circuits for surface, color, and bivariate-bicycle codes that Tesseract is competitive with integer programming-based decoders at moderate physical error rates. Finally, we compare surface and bivariate bicycle codes using most-likely error decoding