Time filter

Source Type

Potenza, Italy

Allevi A.,CNISM | Bondani M.,CNR Institute for Photonics and Nanotechnologies | Andreoni A.,University of Insubria
Optics Letters | Year: 2010

We demonstrate that by using pairs of photodetectors endowed with internal gain we are able to quantify the photon-number correlation coefficient between the two components of a pulsed bipartite state in the "mesoscopic" intensity regime (less than 100 mean photons). We compare the performances of hybrid photoemissive detectors to those of multipixel silicon photon counters and demonstrate that the absence of significant noise allows the evaluation of the variance of the distribution of the differences in photon numbers, and hence of the shot-noise level, without any correction. © 2010 Optical Society of America.

Vasile R.,University of Turku | Maniscalco S.,Heriot - Watt University | Paris M.G.A.,University of Milan | Breuer H.-P.,CNISM | Piilo J.,Albert Ludwigs University of Freiburg
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

We introduce a non-Markovianity measure for continuous-variable open quantum systems based on the idea put forward in H.-P. Breuer, that is, by quantifying the flow of information from the environment back to the open system. Instead of the trace distance we use here the fidelity to assess distinguishability of quantum states. We employ our measure to evaluate non-Markovianity of two paradigmatic Gaussian channels: the purely damping channel and the quantum Brownian motion channel with Ohmic environment. We consider different classes of Gaussian states and look for pairs of states maximizing the backflow of information. For coherent states we find simple analytical solutions, whereas for squeezed states we provide both exact numerical and approximate analytical solutions in the weak coupling limit. © 2011 American Physical Society.

Alfinito E.,University of Salento | Reggiani L.,CNISM | Reggiani L.,University of Salento
Journal of Applied Physics | Year: 2014

The need of new diagnostic methods satisfying, as an early detection, a low invasive procedure and a cost-efficient value, is orienting the technological research toward the use of bio-integrated devices, in particular, bio-sensors. The set of know-why necessary to achieve this goal is wide, from biochemistry to electronics and is summarized in an emerging branch of electronics, called proteotronics. Proteotronics is here applied to state a comparative analysis of the electrical responses coming from type-1 and type-2 opsins. In particular, the procedure is used as an early investigation of a recently discovered family of opsins, the proteorhodopsins activated by blue light, BPRs. The results reveal some interesting and unexpected similarities between proteins of the two families, suggesting the global electrical response are not strictly linked to the class identity. © 2014 AIP Publishing LLC.

Gubbiotti G.,CNISM | Gubbiotti G.,CNR Institute of Materials | Tacchi S.,CNISM | Madami M.,CNISM | And 4 more authors.
Applied Physics Letters | Year: 2012

Spin waves propagating in a bicomponent magnonic crystal consisting of a two-dimensional array of alternated NiFe and Co nanodots have been investigated. The frequency dispersion of collective modes, measured by Brillouin light scattering, is compared with the band diagram obtained by numerically solving the eigenvalue problem derived from the linearized Landau-Lifshitz magnetic torque equation. It is shown that the modes which are active in Brillouin experiment are characterized by the simplest modal profiles within the NiFe dots. For such excitations, the Co dots act as mediators of dipole coupling between the NiFe dots. © 2012 American Institute of Physics.

Gubbiotti G.,CNISM | Tacchi S.,CNISM | Madami M.,CNISM | Carlotti G.,University of Perugia | And 3 more authors.
Journal of Physics D: Applied Physics | Year: 2010

The application of Brillouin light scattering to the study of the spin-wave spectrum of one-and two-dimensional planar magnonic crystals consisting of arrays of interacting stripes, dots and antidots is reviewed. It is shown that the discrete set of allowed frequencies of an isolated nanoelement becomes a finite-width frequency band for an array of identical interacting elements. It is possible to tune the permitted and forbidden frequency bands, modifying the geometrical or the material magnetic parameters, as well as the external magnetic field. From a technological point of view, the accurate fabrication of planar magnonic crystals and a proper understanding of their magnetic excitation spectrum in the gigahertz range is oriented to the design of filters and waveguides for microwave communication systems. © 2010 IOP Publishing Ltd.

Discover hidden collaborations