When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Choi's theorem on completely positive maps - Wikipedia

    en.wikipedia.org/wiki/Choi's_theorem_on...

    In mathematics, Choi's theorem on completely positive maps is a result that classifies completely positive maps between finite-dimensional (matrix) C*-algebras. An infinite-dimensional algebraic generalization of Choi's theorem is known as Belavkin 's "Radon–Nikodym" theorem for completely positive maps.

  3. Quantum operation - Wikipedia

    en.wikipedia.org/wiki/Quantum_operation

    Mathematically, a quantum operation is a linear map Φ between spaces of trace class operators on Hilbert spaces H and G such that. If S is a density operator, Tr (Φ (S)) ≤ 1. Φ is completely positive, that is for any natural number n, and any square matrix of size n whose entries are trace-class operators and which is non-negative, then is ...

  4. Quantum channel - Wikipedia

    en.wikipedia.org/wiki/Quantum_channel

    Quantum channel. In quantum information theory, a quantum channel is a communication channel which can transmit quantum information, as well as classical information. An example of quantum information is the general dynamics of a qubit. An example of classical information is a text document transmitted over the Internet.

  5. AuthaGraph projection - Wikipedia

    en.wikipedia.org/wiki/AuthaGraph_projection

    An approximation of the AuthaGraph projection. AuthaGraph is an approximately equal-area world map projection invented by Japanese architect Hajime Narukawa [1] in 1999. [2] The map is made by equally dividing a spherical surface into 96 triangles, transferring it to a tetrahedron while maintaining area proportions, and unfolding it in the form of a rectangle: it is a polyhedral map projection.

  6. Trace inequality - Wikipedia

    en.wikipedia.org/wiki/Trace_inequality

    Jensen's trace inequality. Let f be a continuous function defined on an interval I and let m and n be natural numbers. If f is convex, we then have the inequality. for all (X1, ... , Xn) self-adjoint m × m matrices with spectra contained in I and all (A1, ... , An) of m × m matrices with.

  7. Wigner quasiprobability distribution - Wikipedia

    en.wikipedia.org/wiki/Wigner_quasiprobability...

    Wigner function of a so-called cat state. The Wigner quasiprobability distribution (also called the Wigner function or the Wigner–Ville distribution, after Eugene Wigner and Jean-André Ville) is a quasiprobability distribution. It was introduced by Eugene Wigner in 1932 [1] to study quantum corrections to classical statistical mechanics.

  8. Hermitian matrix - Wikipedia

    en.wikipedia.org/wiki/Hermitian_matrix

    Hermitian matrices are applied in the design and analysis of communications system, especially in the field of multiple-input multiple-output (MIMO) systems. Channel matrices in MIMO systems often exhibit Hermitian properties. In graph theory, Hermitian matrices are used to study the spectra of graphs. The Hermitian Laplacian matrix is a key ...

  9. Entanglement witness - Wikipedia

    en.wikipedia.org/wiki/Entanglement_witness

    A mixed state ρ is then a trace-class positive operator on the state space which has trace 1. We can view the family of states as a subset of the real Banach space generated by the Hermitian trace-class operators, with the trace norm. A mixed state ρ is separable if it can be approximated, in the trace norm, by states of the form