412 research outputs found

    On the generation of random ensembles of qubits and qutrits Computing separability probabilities for fixed rank states

    Full text link
    The question of the generation of random mixed states is discussed, aiming for the computation of probabilistic characteristics of composite finite dimensional quantum systems. Particularly, we consider the generation of the random Hilbert-Schmidt and Bures ensembles of qubit and qutrit pairs and compute the corresponding probabilities to find a separable state among the states of a fixed rank

    On the stratifications of 2-qubits X-state space

    Get PDF
    The 7-dimensional family PX\mathfrak{P}_X of so-called mixed X-states of 2-qubits is considered. Two types of stratification of 2-qubits Xβˆ’X-state space, i.e., partitions of PX \mathfrak{P}_X\, into orbit types with respect to the adjoint group actions, one of the global unitary group GXβŠ‚SU(4)G_X \subset SU(4) and another one under the action of the local unitary group LGXβŠ‚GXLG_X \subset G_X, is described. The equations and inequalities in the invariants of the corresponding groups, determining each stratification component, are given

    On the family of Wigner functions for N-level quantum system

    Full text link
    The family of unitary non-equivalent Weyl-Stratonovich kernels determining the Wigner probability distribution function of an arbitrary N-level quantum system is constructed
    • …