Industry/government seminar on Large Space systems technology: Executive summary

The critical technology developments which the participating experts recommend as being required to support the early generation large space systems envisioned as space missions during the years 1985-2000 are summarized

THEORY OF HYPERSONIC LAMINAR STAGNATION REGION HEAT TRANSFER IN DISSOCIATING GASES

Thermochemical effects of foreign planetary atmospheres upon laminar heat transfer in hypersonic stagnation region - gas dynamic

GHZGHZ state generation of three Josephson qubits in presence of bosonic baths

We analyze an entangling protocol to generate tripartite Greenberger-Horne-Zeilinger states in a system consisting of three superconducting qubits with pairwise coupling. The dynamics of the open quantum system is investigated by taking into account the interaction of each qubit with an independent bosonic bath with an ohmic spectral structure. To this end a microscopic master equation is constructed and exactly solved. We find that the protocol here discussed is stable against decoherence and dissipation due to the presence of the external baths.Comment: 16 pages and 4 figure

Dissipation and entanglement dynamics for two interacting qubits coupled to independent reservoirs

We derive the master equation of a system of two coupled qubits by taking into account their interaction with two independent bosonic baths. Important features of the dynamics are brought to light, such as the structure of the stationary state at general temperatures and the behaviour of the entanglement at zero temperature, showing the phenomena of sudden death and sudden birth as well as the presence of stationary entanglement for long times. The model here presented is quite versatile and can be of interest in the study of both Josephson junction architectures and cavity-QED.Comment: 14 pages, 3 figures, submitted to Journal of Physics A: Mathematical and Theoretica

Il ruolo dell’Architettura nella gestione dei Commons: un’ipotesi per lo “Scugnizzo liberato”.

Nel 2013 il Comune di Napoli ha istituito l’Osservatorio sui beni comuni, con quest’atto viene ufficializzata una posizione innovativa, ma anche fortemente controversa, relativa alla gestione di beni di proprietà pubblica o privata da parte di “comunità” che utilizzano questi spazi realizzando un utile sociale. Il numero di Louts del 1994 dal titolo Commons traccia la relazione tra questa questione, di natura economica, politica e sociale e l’architettura. In particolare a Napoli i nove spazi individuati dall’Osservatorio pongono agli architetti nuove domande e, prima tra tutte, come conciliare questa modalità di gestione dal basso, che ha sicuramente il merito di restituire alla comunità luoghi spesso dimenticati e abbandonati, con le esigenze di tutela e conservazione del patrimonio culturale della città. Partendo dal caso dello” scugnizzo liberato” l'intervento proverà a definire un possibile ruolo dell’architettura nel processo di gestione dei Commons

Free Molecule Heat Transfer in the Ionosphere

Free molecular heat transfer and mass flux at vehicle surface during ionospheric entr

Population trapping due to cavity losses

In population trapping the occupation of a decaying quantum level keeps a constant non-zero value. We show that an atom-cavity system interacting with an environment characterized by a non-flat spectrum, in the non-Markovian limit, exhibits such a behavior, effectively realizing the preservation of nonclassical states against dissipation. Our results allow to understand the role of cavity losses in hybrid solid state systems and pave the way to the proper description of leakage in the recently developed cavity quantum electrodynamic systems.Comment: 4 pages, 3 figures, version accepted for publication on Phys. Rev.

Entanglement Dynamics of Two Independent Cavity-Embedded Quantum Dots

We investigate the dynamical behavior of entanglement in a system made by two solid-state emitters, as two quantum dots, embedded in two separated micro-cavities. In these solid-state systems, in addition to the coupling with the cavity mode, the emitter is coupled to a continuum of leaky modes providing additional losses and it is also subject to a phonon-induced pure dephasing mechanism. We model this physical configuration as a multipartite system composed by two independent parts each containing a qubit embedded in a single-mode cavity, exposed to cavity losses, spontaneous emission and pure dephasing. We study the time evolution of entanglement of this multipartite open system finally applying this theoretical framework to the case of currently available solid-state quantum dots in micro-cavities.Comment: 10 pages, 4 figures, to appear in Topical Issue of Physica Scripta on proceedings of CEWQO 201

Brownian Dynamics Simulation of Polydisperse Hard Spheres

Standard algorithms for the numerical integration of the Langevin equation require that interactions are slowly varying during to the integration timestep. This in not the case for hard-body systems, where there is no clearcut between the correlation time of the noise and the timescale of the interactions. Starting from a short time approximation of the Smoluchowsky equation, we introduce an algorithm for the simulation of the overdamped Brownian dynamics of polydisperse hard-spheres in absence of hydrodynamics interactions and briefly discuss the extension to the case of external drifts