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IQI Weekly Seminar

Tuesday, January 21, 2020
3:00pm to 4:00pm
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Annenberg 107
Using redundant ancilla encoding and flags for low overhead magic state preparation
Christopher Chamberland, Researcher, Amazon Quantum Group,

Abstract: The overhead cost of performing universal fault-tolerant quantum computation for large scale algorithms is very high. Despite several attempts at alternative schemes, magic state distillation remains one of the most efficient schemes for simulating non-Clifford gates fault-tolerantly. However, since magic state distillation circuits are not fault-tolerant, all Clifford operations must be encoded in a large distance code in order to have comparable failure rates with the magic states being distilled. In this work, we introduce a new concept which we call redundant ancilla encoding. The latter combined with flag qubits allows for circuits to both measure stabilizer generators of some code, while also being able to measure global operators to fault-tolerantly prepare magic states, all using nearest neighbor interactions. In particular, we apply such schemes to the triangular color code family. Such schemes are suitable for experimental implementations and are expected to significantly reduce the overhead for preparing high-fidelity magic states. Extensive numerical study to substantiate the resource reduction is underway.

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