2015/12/22 by Davide Orsucci, Markus Tiersch, Hans J. Briegel · 15 citations
Computer Science · Mathematics · Physics and Astronomy · #Algorithm #Bloch sphere #Coherence (philosophical gambling strategy) #Combinatorics #Computation #Computer science #Mathematics #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum computer #Quantum information #Quantum mechanics #Qubit #Topology (electrical circuits) #Unitary state #quant-ph
paper · pdf · doi:10.1103/physreva.93.042303
published in Physical Review A 93(4) (American Physical Society) · 18 pages, 3 figures, 3 tables
arxiv created 2015/12/22 · openalex publication_date 2016/04/01 · arxiv updated 2016/04/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In the context of measurement-based quantum computation a way of maintaining the coherence of a graph state is to measure its stabilizer operators. Aside from performing quantum error correction, it is possible to exploit the information gained from these measurements to characterize and then counteract a coherent source of errors; that is, to determine all the parameters of an error channel that applies a fixed---but unknown---unitary operation to the physical qubits. Such a channel is generated, e.g., by local stray fields that act on the qubits. We study the case in which each qubit of a given graph state may see a different error channel and we focus on channels given by a rotation on the Bloch sphere around either the \stackrel\ifmmode \else \\fi\mathbitx, the \stackrel\ifmmode \else \\fi\mathbity, or the \stackrel\ifmmode \else \\fi\mathbitz axis, for which analytical results can be given in a compact form. The possibility of reconstructing the channels at all qubits depends nontrivially on the topology of the graph state. We prove via perturbation methods that the reconstruction process is robust and supplement the analytic results with numerical evidence.