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Abstract: Within the framework of constructions for quantifying entanglement, we build a natural scenario for the assembly of multipartite entanglement measures based on Hopf bundle-like mappings obtained through Clifford algebra representations. Then, given the non-factorizability of an arbitrary two-qubit density matrix, we give an alternate quantity that allows the construction of two types of entanglement measures based on their arithmetical and geometrical averages over all pairs of qubits in a register of size N, and thus fully characterize its degree and type of entanglement. We find that such an arithmetical average is both additive and strongly super additive. [Copyright &y& Elsevier]

Resonant energy transfer mechanisms have been observed in the sensitized luminescence of solids, and in quantum dots, molecular nanostructures, and photosynthetic organisms. We demonstrate that such mechanisms, together with the exciton–exciton binding energy shift typical of these nanostructures, can be used to perform universal quantum logic and generate quantum entanglement. [Copyright &y& Elsevier]

Abstract: With the aim of characterizing quantum entanglement in multipartite systems, we introduce a measure of total correlations and analyze its advantages, comparing it to other measures of multipartite total correlations reported in the literature. In this context, the role of pairwise correlations is discussed, in particular with a view to implementing quantum communication protocols. [Copyright &y& Elsevier]

Abstract: We provide a full numerical characterization of non-Markovian quantum decoherence for a two-level (qubit) system coupled to a tailorable reservoir by studying the influence of different factors, such as system–reservoir coupling and temperature. The necessity of a decoherence analysis from short to long time ranges and for a large set of parameters are fundamental requirements for quantum information processing in order to produce a controlled conditional quantum dynamics. We show how the Feynman–Vernon influence functional technique can be used in order to obtain a numerical algorithm that enables a full characterization of non-Markovian processes. This analysis paves the way for modeling the prevention and control of decoherence in solid-state systems with ultrafast dynamics and strong environmental coupling. [Copyright &y& Elsevier]

Abstract: Within the density matrix formalism, we report on the quantum control of the excitonic coherences in quantum dots coupled to a single mode field resonant semiconductor cavity. We use an external classical laser field to drive the dynamical response of the excitonic states. Dissipation mechanisms associated with the cavity field and the excitonic states are explicitly included in the model. Our numerical simulations of the excitonic dynamics are in good agreement with recent experimental reports. Furthermore, we compute and show how to tailor such a dynamics in the presence of the laser field by means of controlling the detuning between the laser and the cavity field frequencies. The results are analyzed with a view to implementing quantum control of local qubit operations. [Copyright &y& Elsevier]