Giorgi G.L.,INRIM - Istituto Nazionale di Ricerca Metrologica
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013
The role played by quantum discord in mixed-state computation is widely debated since, in spite of evidence of its importance in creating quantum advantages, even in the absence of entanglement, there are not direct proofs of its necessity in these computational tasks. Recently, the presence of discord was shown to be necessary and sufficient for remote state preparation for a broad class of quantum channels. Here, we show that this property is not universal. There are states whose discord cannot be considered as a quantum resource since it has been produced locally that are useful for remote state preparation, and there are bona fide discordant states that are of no help. © 2013 American Physical Society.
Bich W.,INRIM - Istituto Nazionale di Ricerca Metrologica
IEEE Transactions on Instrumentation and Measurement | Year: 2012
The concept of uncertainty in measurement stems from that of (probable) error and is intimately intertwined with it. Both concepts can be viewed as measures of the quality of a measurement or, better, of the corresponding estimate. There is an endless list of misunderstandings, false beliefs, and misinterpretations on this subject. People tend also to use the same word with different meanings. In this paper, while giving an overview of the evolution of the concept, from the initial unawareness of the need for a quality assessment (still present in many areas) to the present views, the author also tries to shed some light and some clarity on the most popular and debated misunderstandings, particularly about the concepts of error, true quantity value(s), and measured quantity value. The author is the convener of the Joint Committee for Guides in Metrology Working Group 1 (Guide to the expression of uncertainty in measurement). The opinion expressed in this paper does not necessarily represent the view of this working group. © 1963-2012 IEEE.
Basso V.,INRIM - Istituto Nazionale di Ricerca Metrologica
Journal of Physics Condensed Matter | Year: 2011
This paper presents a study of the magnetocaloric effect at the first-order magneto-elastic phase transition. The entropy change Δs at the transition temperature is given by the sum of the magnetic and the structural contributions. By using a thermodynamic model, it is shown that the sign and amplitude of the structural contribution to Δs are determined by the dimensionless parameter ζ (zeta) which depends on β, the steepness of the change of exchange forces with volume, and on αp, the thermal expansion coefficient of the structural lattice. For ζ < 0 the change Δs can be larger than the magnetic contribution alone, because the structural entropy change and the magnetic entropy change have the same sign, giving rise to the giant magnetocaloric effect. For 0 < ζ < 1 the two contributions partially cancel each other and the total entropy change is lower than the magnetic entropy change. For ζ > 1 the structural entropy dominates and a transition occurs upon heating from a low temperature paramagnet to a high temperature ferromagnet. © 2011 IOP Publishing Ltd.
D'Errico G.E.,INRIM - Istituto Nazionale di Ricerca Metrologica
IEEE Transactions on Industrial Electronics | Year: 2012
In-process treatment of measurement data is a challenging topic of industrial metrology. In the present research work, simultaneous estimation of measurand and related uncertainty is targeted from a measurement science standpoint. A metrological customization of the Kalman filter technique is implemented with application to basic coordinate measuring machine tasks. This is shown to accomplish Bayesian integration of the expert's preprocess knowledge and in-process measurement results-akin to type B and type A uncertainty evaluation in the framework of the Joint Committee for Guides in Metrology Guide to the expression of uncertainty in measurement, respectively. Uncertainty assessment is automated accordingly. Based on recursive processing of fresh data only, relevant advantages are real-time performance and memory saving. © 2011 IEEE.
Agency: Cordis | Branch: FP7 | Program: CP-IP | Phase: NMP.2013.1.4-2 | Award Amount: 5.67M | Year: 2013
According to European Commission [EC, COM (2012) 572, 3.10.2012] important challenges at European level are related to the establishment of validated method and instrumentation for detection, characterization and analysis of nanoparticles. In the framework of the SETNanometro project, the use of various measurement techniques for the determination of the NPs properties will allow to move from the currently used trial and error approach toward the development of well defined and controlled protocols for the production of TiO2 NPs. A particular care will be devoted to the establishment of correct metrological traceability chain in order to ensure the reliability of the results. The lack of international measurement standards for calibration is an aspect of particular relevance in nanotechnologies as it is difficult to select a universal calibration artefact to achieve repeatability at nanoscale. The materials produced according to such procedures, will be hence sufficiently characterised and homogeneous in their properties to become candidate Certified Reference Materials to be used in various applications where the lack of metrological traceability is encountered. The project results are expected to lead to fundamental impacts on the following areas: Environment: the increased knowledge of TiO2 NPs will improve the photocatalytic properties for the treatment of pollutants in air and water Energy: the better knowledge of dimension and electronic structure of TiO2 will allow to improve the traceability of DSSC measurements. Health: the engineering of topographic and surface composition of TiO2 nanostructured coatings of orthopaedic and dental prostheses will support the design of rules for the production of devices exhibiting otpimized interfacial properties for a better and quicker integration of the implants in the hosting bone tissues.