Magic state distillation falters with noisy quantum measurements

Yunzhe Zheng of Tsinghua University and Yale University, along with colleagues, have demonstrated a critical limitation in the leading method for building fault-tolerant quantum computers: magic state distillation. The work reveals that imperfect measurements introduce a threshold of measurement strength distinct from the previously known threshold on input-state error. When measurement strength falls below this threshold, magic state distillation entirely loses its ability to create useful, distilled states; even above it, the resulting states deviate from ideal quality, though this deviation remains limited to being "at most first-order biased". These findings highlight fundamental constraints imposed by realistic quantum hardware and offer guidance for designing more…