Conditions for the confirmation of three-particle non-locality

The notion of genuine three-particle non-locality introduced by Svetlichny \cite{Svetlichny} is discussed. Svetlichny's inequality which can distinguish between genuine three-particle non-locality and two-particle non-locality is analyzed by reinterpreting it as a frustrated network of correlations. Its quantum mechanical maximum violation is derived and a situation is presented that produces the maximum violation. It is shown that the measurements performed in recent experiments to demonstrate GHZ entanglement \cite{Bouwmeester}, \cite{Pan} do not allow this inequality to be violated, and hence can not be taken as confirmation of genuine three-particle non-locality. Modifications to the experiments that would make such a confirmation possible are discussed.Comment: minor revisions, references adde

Parameter estimation method using an extended Kalman Filter

Fast parameter estimation is a non-trivial task, and it is critical when the system parameters evolve with time, as demanded in real-time control applications. In this study, a new computational approach for parameter identification is proposed based on the application of polynomial chaos theory. The polynomial chaos approach has been shown to be considerably more efficient than Monte Carlo in the simulation of systems with a small number of uncertain parameters. In the framework of this new approach, a (suboptimal) Extended Kalman Filter (EKF) is used to recalculate the polynomial chaos expansions for the uncertain states and the uncertain parameters. As a case study, the proposed parameter estimation method is applied to a four degree-of-freedom roll plane model of a vehicle for which the vertical stiffnesses of the tires are estimated from periodic observations of the displacements and velocities across the suspensions. The results obtained with this approach are close to the actual values of the parameters. In addition, the EKF approach gives more information about the parameters of interest than a simple estimated value: the estimation comes in the form of a probability density function. The approach presented in this paper has shown great promise for an improvement in the computational efficiency of current parameter estimation methods. Possible applications of this theory to the field of off-road vehicle simulations include the estimation of various vehicle parameters of interest, as well as the estimation of parameters related to the tire-terrain contact

Dynamics of a two-level system coupled with a quantum oscillator in the very strong coupling limit

The time-dependent behavior of a two-level system interacting with a quantum oscillator system is analyzed in the case of a coupling larger than both the energy separation between the two levels and the energy of quantum oscillator ($\Omega < \omega < \lambda$, where $\Omega$ is the frequency of the transition between the two levels, $\omega$ is the frequency of the oscillator, and $\lambda$ is the coupling between the two-level system and the oscillator). Our calculations show that the amplitude of the expectation value of the oscillator coordinate decreases as the two-level system undergoes the transition from one level to the other, while the transfer probability between the levels is staircase-like. This behavior is explained by the interplay between the adiabatic and the non-adiabatic regimes encountered during the dynamics with the system acting as a quantum counterpart of the Landau-Zener model. The transition between the two levels occurs as long as the expectation value of the oscillator coordinate is driven close to zero. On the contrary, if the initial conditions are set such that the expectation values of the oscillator coordinate are far from zero, the system will remain locked on one level.Comment: 4 pages, 4 figures, to be published in Physical Review

Nb-doped TiO2 thin films deposited by spray pyrolysis method

Undoped TiO2 and Nb-doped TiO2 thin films have been deposited by spray pyrolysis method on ITO/glass substrates. All the as-deposited films are amorphous, as shown by X-Ray Diffraction. Under certain conditions of heat-treatment in air, the films deposited by pyrolysis became pure anatase. The hydrophilic properties of all the films were investigated, and a comparison was made as a function of the heat treatment, and as a function of Nb doping. Contact angles lower then 3 deg. have been obtained, after irradiation times specific for each film

Sequential weak measurement

The notion of weak measurement provides a formalism for extracting information from a quantum system in the limit of vanishing disturbance to its state. Here we extend this formalism to the measurement of sequences of observables. When these observables do not commute, we may obtain information about joint properties of a quantum system that would be forbidden in the usual strong measurement scenario. As an application, we provide a physically compelling characterisation of the notion of counterfactual quantum computation