Articolele autorului Iulia Ghiu
Link la profilul stiintific al lui Iulia Ghiu

Probing light polarization with the quantum Chernoff bound

We recall the framework of a consistent quantum description of polarization of light. Accordingly, the degree of polarization of a two-mode state $hat rho$ of the quantum radiation field can be defined as a distance of a related state ${hat rho}_b$ to the convex set of all SU(2) invariant two-mode states. We explore a distance-type polarization measure in terms of the quantum Chernoff bound and derive its explicit expression. A comparison between

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Local transformations of superpositions of entangled states
Quantum Chernoff bound as a measure of nonclassicality for one-mode Gaussian states

We evaluate a Gaussian distance-type degree of nonclassicality for a single-mode Gaussian state of the quantum radiation field by use of the recently discovered quantum Chernoff bound. The general properties of the quantum Chernoff overlap and its relation to the Uhlmann fidelity are interestingly illustrated by our approach.

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Broadcasting of entanglement at a distance using linear optics and telecloning of entanglement

We propose a scheme for broadcasting entanglement at a distance based on linear optics. We show that an initial polarization entangled state can be simultaneously split and transmitted to a pair of observers situated at different locations with the help of two conditional Bell-state analyzers based on two beam splitters characterized by the same reflectivity R. In particular for R=1/3, the final states coincide with the output states obtained by

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Asymmetric quantum telecloning of d-level systems and broadcasting of entanglement to different locations using the „many-to-many” communication protocol

We propose a generalization of quantum teleportation: the so-called many-to-many quantum communication of the information of a d-level system from N spatially separated senders to M>N receivers situated at different locations. We extend the concept of asymmetric telecloning from qubits to d-dimensional systems. We investigate the broadcasting of entanglement by using local 1->2 optimal universal asymmetric Pauli machines and show that the maximal

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Entanglement-assisted local transformations between inequivalent classes of three-particle entangled states

We show that bipartite and tripartite entangled states cannot be used as catalysis states to enable local transformations inbetween inequivalent classes of three-particle entangled states which are non-interchangeable under local transformations. We find the optimal protocol for conversion of a certain family of the W-states and an EPR-pair into the GHZ-state.

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