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Quantum accuracy threshold for concatenated distance-3 codes

Panos Aliferis·Daniel Gottesman·John Preskill
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Abstract

We prove a new version of the quantum threshold theorem that applies to concatenation of a quantum code that corrects only one error, and we use this theorem to derive a rigorous lower bound on the quantum accuracy threshold epsilon_0. Our proof also applies to concatenation of higher-distance codes, and to noise models that allow faults to be correlated in space and in time. The proof uses new criteria for assessing the accuracy of fault-tolerant circuits, which are particularly conducive to the inductive analysis of recursive simulations. Our lower bound on the threshold, epsilon_0 > 2.73 \times 10^{-5} for an adversarial independent stochastic noise model, is derived from a computer-assisted combinatorial analysis; it is the best lower bound that has been rigorously proven so far.

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Panos Aliferis, Daniel Gottesman, John Preskill. 2005-10-21. Quantum accuracy threshold for concatenated distance-3 codes. https://arxiv.org/abs/quant-ph/0504218

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