Upper Bounds on the Noise Threshold for Fault-tolerant Quantum Computing

dc.creatorKempe, Julia
dc.creatorRegev, Oded
dc.creatorUnger, Falk
dc.creatorde Wolf, Ronald
dc.date2008-02-11
dc.date.accessioned2026-07-07T09:19:55Z
dc.date.available2026-07-07T09:19:55Z
dc.descriptionWe prove new upper bounds on the tolerable level of noise in a quantum circuit. We consider circuits consisting of unitary k-qubit gates each of whose input wires is subject to depolarizing noise of strength p, as well as arbitrary one-qubit gates that are essentially noise-free. We assume that the output of the circuit is the result of measuring some designated qubit in the final state. Our main result is that for p>1-Θ(1/\sqrt{k}), the output of any such circuit of large enough depth is essentially independent of its input, thereby making the circuit useless. For the important special case of k=2, our bound is p>35.7%. Moreover, if the only allowed gate on more than one qubit is the two-qubit CNOT gate, then our bound becomes 29.3%. These bounds on p are notably better than previous bounds, yet are incomparable because of the somewhat different circuit model that we are using. Our main technique is the use of a Pauli basis decomposition, which we believe should lead to further progress in deriving such bounds.
dc.description14 pages, 3 figures
dc.identifierhttps://arxiv.org/abs/0802.1464
dc.identifierhttp://arxiv.org/abs/0802.1464
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/154570
dc.subjectQuantum Physics
dc.titleUpper Bounds on the Noise Threshold for Fault-tolerant Quantum Computing
dc.typetext

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