Now showing items 1-6 of 6

  • Directed graph representation of half-rate additive codes over GF(4) 

    Danielsen, Lars Eirik; Parker, Matthew G. (Springer, 2010)
    We show that (n, 2n) additive codes over GF(4) can be represented as directed graphs. This generalizes earlier results on self-dual additive codes over GF(4), which correspond to undirected graphs. Graph representation ...
  • On Connections Between Graphs, Codes, Quantum States, and Boolean Functions 

    Danielsen, Lars Eirik (The University of Bergen, 2008-05-28)
    We study objects that can be represented as graphs, error-correcting codes, quantum states, or Boolean functions. It is known that self-dual additive codes, which can also be interpreted as quantum states, can be ...
  • On Self-Dual Quantum Codes, Graphs, and Boolean Functions 

    Danielsen, Lars Eirik (The University of Bergen, 2005)
    A short introduction to quantum error correction is given, and it is shown that zero-dimensional quantum codes can be represented as self-dual additive codes over GF(4) and also as graphs. We show that graphs representing ...
  • On the Classification of Hermitian Self-Dual Additive Codes over GF(9) 

    Danielsen, Lars Eirik (Institute of Electrical and Electronics Engineers, 2012-08)
    Additive codes over GF(9) that are self-dual with respect to the Hermitian trace inner product have a natural application in quantum information theory, where they correspond to ternary quantum error-correcting codes. ...
  • Optimal preparation of graph states 

    Cabello, Adán; Danielsen, Lars Eirik; López-Tarrida, Antonio J.; Portillo, José R. (American Physical Society, 2011-04-12)
    We show how to prepare any graph state of up to 12 qubits with: (a) the minimum number of controlled-Z gates, and (b) the minimum preparation depth. We assume only one-qubit and controlled-Z gates. The method exploits ...
  • Quantum social networks 

    Cabello, Adán; Danielsen, Lars Eirik; López-Tarrida, Antonio J.; Portillo, José R. (Institute of Physics, 2012-06-27)
    We introduce a physical approach to social networks (SNs) in which each actor is characterized by a yes–no test on a physical system. This allows us to consider SNs beyond those originated by interactions based on pre-existing ...