2018/11/30 by Christopher Chamberland, Andrew W. Cross · 5 citations
Computer Science · Physics and Astronomy · #Distillation #MAGIC (telescope) #Overhead (engineering) #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum computer #Quantum-Dot Cellular Automata #Qubit #Scheme (mathematics) #State (computer science) #quant-ph
paper · pdf · doi:10.22331/q-2019-05-20-143
published as Quantum 3, 143 (2019) · 26 pages, 17 figures, 5 tables. Comments welcome! v2 (published version): quantumarticle documentclass and expanded discussions on the fault-tolerant schemes
openalex created_date 2018/11/09 · arxiv created 2019/05/14 · openalex publication_date 2019/05/20 · arxiv updated 2019/05/22 · openalex updated_date 2026/08/05
Magic state distillation is one of the leading candidates for implementing universal fault-tolerant logical gates. However, the distillation circuits themselves are not fault-tolerant, so there is additional cost to first implement encoded Clifford gates with negligible error. In this paper we present a scheme to fault-tolerantly and directly prepare magic states using flag qubits. One of these schemes requires only three ancilla qubits, even with noisy Clifford gates. We compare the physical qubit and gate cost of our scheme to the magic state distillation protocol of Meier, Eastin, and Knill (MEK), which is efficient and uses a small stabilizer circuit. For low enough noise rates, we show that in some regimes the overhead can be improved by several orders of magnitude compared to the MEK scheme which uses Clifford operations encoded in the codes considered in this work.