Linear and nonlinear coupling of quantum dots in microcavities

We discuss the topical and fundamental problem of strong-coupling between a quantum dot an the single mode of a microcavity. We report seminal quantitative descriptions of experimental data, both in the linear and in the nonlinear regimes, based on a theoretical model that includes pumping and quantum statistics.Comment: Proceedings of the symposium Nanostructures: Physics and Technology 2010 (http://www.ioffe.ru/NANO2010), 2 pages in proceedings styl

Brand Network Booster: A New System for Improving Brand Connectivity

This paper presents a new decision support system offered for an in-depth analysis of semantic networks, which can provide insights for a better exploration of a brand's image and the improvement of its connectivity. In terms of network analysis, we show that this goal is achieved by solving an extended version of the Maximum Betweenness Improvement problem, which includes the possibility of considering adversarial nodes, constrained budgets, and weighted networks - where connectivity improvement can be obtained by adding links or increasing the weight of existing connections. We present this new system together with two case studies, also discussing its performance. Our tool and approach are useful both for network scholars and for supporting the strategic decision-making processes of marketing and communication managers

New experimental diagnostics in combustion of forest fuels: microscale appreciation for a macroscale approach

In modelling the wildfire behaviour, good knowledge of the mechanisms and the kinetic parameters controlling the thermal decomposition of forest fuel is of great importance. The kinetic modelling is based on the mass-loss rate, which defines the mass-source term of combustible gases that supply the flames and influences the propagation of wildland fires. In this work, we investigated the thermal degradation of three different fuels using a multi-scale approach.Lab-scale experimental diagnostics such as thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), use of the cone calorimeter (CC) or Fire Propagation Apparatus (FPA) led to valuable results for modelling the thermal degradation of vegetal fuels and allowed several upgrades of pyrolysis models.However, this work remains beyond large-scale conditions of a wildland or forest fire. In an effort to elaborate on the kinetic models under realistic natural fire conditions, a mass-loss device specifically designed for the field scale has been developed. The paper presents primary results gained using this new device, during large-scale experiments of controlled fires. The mass-loss records obtained on a field scale highlight the influence of the chemical composition and the structure of plants. Indeed, two species with similar chemical and morphological characteristics exhibit similar mass-loss rates, whereas the third presents different thermal behaviour.The experimental data collected at a field scale led to a new insight about thermal degradation processes of natural fuel when compared to the kinetic laws established in TGA. These new results provide a global description of the kinetics of degradation of Mediterranean forest fuels. The results led to a proposed thermal degradation mechanism that has also been validated on a larger scale.</p

NEW RECORDS OF NATIVE AND ALIEN VASCULAR PLANTS FROM ABRUZZO, LAZIO AND MOLISE NATIONAL PARK (ITALY) - AND ADDITIONS TO THE FLORA OF ABRUZZO AND MOLISE ADMINISTRATIVE REGIONS

The Abruzzo, Lazio and Molise National Park, a flagship conservation area in Italy, is a hotspot of floristic diversity and a crossroad for plant biogeography. In this work, as a result of recent field studies in the Park and herbarium revisions, we report 10 taxa new or confirmed for the Abruzzo administrative region, and 3 for the Molise administrative region. Moreover. 47 taxa of vascular plants (41 native and 6 alien taxa) that are new or confirmed for the flora of the Park are reported. Five taxa are excluded from the flora of the Park

Full Stark control of polariton states on a spin-orbit hypersphere

The orbital angular momentum and the polarization of light are physical quantities widely investigated for classical and quantum information processing. In this work we propose to take advantage of strong light-matter coupling, circular-symmetric confinement, and transverse-electric transverse-magnetic splitting to exploit states where these two degrees of freedom are combined. To this end we develop a model based on a spin-orbit Poincaré hypersphere. Then we consider the example of semiconductor polariton systems and demonstrate full ultrafast Stark control of spin-orbit states. Moreover, by controlling states on three different spin-orbit spheres and switching from one sphere to another we demonstrate the control of different logic bits within one single physical system

Two-dimensional quantum oscillations of the conductance at LaAlO3/SrTiO3 interfaces

We report on a study of magnetotransport in LaAlO3/SrTiO3 interfaces characterized by mobilities of the order of several thousands cm$^{2}$/Vs. We observe Shubnikov-de Haas oscillations that indicate a two-dimensional character of the Fermi surface. The frequency of the oscillations signals a multiple sub-bands occupation in the quantum well or a multiple valley configuration. From the temperature dependence of the oscillation amplitude we extract an effective carrier mass $m^{*}\simeq1.45$\,$m_{e}$. An electric field applied in the back-gate geometry increases the mobility, the carrier density and the oscillation frequency.Comment: 4 pages, 4 figure

Nanodot-Cavity Electrodynamics and Photon Entanglement

Quantum electrodynamics of excitons in a cavity is shown to be relevant to quantum operations. We present a theory of an integrable solid-state quantum controlled-phase gate for generating entanglement of two photons using a coupled nanodot-microcavity-fiber structure. A conditional phase shift of $O(\pi/10)$ is calculated to be the consequence of the giant optical nonlinearity keyed by the excitons in the cavities. Structural design and active control, such as electromagnetic induced transparency and pulse shaping, optimize the quantum efficiency of the gate operation.Comment: 4 pages 3 figure

Drag in a resonantly driven polariton fluid

We study the linear response of a coherently driven polariton fluid in the pump-only configuration scattering against a point-like defect and evaluate analytically the drag force exerted by the fluid on the defect. When the system is excited near the bottom of the lower polariton dispersion, the sign of the interaction-renormalised pump detuning classifies the collective excitation spectra into three different categories (Ciuti and Carusotto 2005 Phys. Status Solidi b 242 2224): linear for zero, diffusive-like for positive and gapped for negative detuning. We show that both cases of zero and positive detuning share a qualitatively similar crossover of the drag force from the subsonic to the supersonic regime as a function of the fluid velocity, with a critical velocity given by the speed of sound found for the linear regime. In contrast, for gapped spectra, we find that the critical velocity exceeds the speed of sound. In all cases, the residual drag force in the subcritical regime depends on the polariton lifetime only. Also, well below the critical velocity, the drag force varies linearly with the polariton lifetime, in agreement with previous work (Cancellieri et al 2010 Phys. Rev. B 82 224512), where the drag was determined numerically for a finite-size defect

Italian food? Sounds good! Made in Italy and Italian sounding effects on food products' assessment by consumers

Italian Sounding—i. e., the Italian appearance of a product or service brand irrespective of its country of origin—represents a global market phenomenon affecting a wide range of economic sectors, particularly the agro-food sector. Although its economic impact has been repeatedly stressed from different points of view (policy, economy, culture, etc.), systematic scientific knowledge regarding its social–psychological bases is lacking. Three studies carried out in three different countries (Italy, China, and USA) address this literature gap. Different consumer groups (both native and/or non-native) are targeted regarding major product categories pre-selected categories, which are the major Italian food goods within the specific country according to piloting (oil and/or pasta). In each study, the main independent variable (product version) has been manipulated by presenting real product images (previously pre-selected within the tested food category in each country market), whose “Italianness” degree is effectively manipulated by the main study variable (product version) across three or four levels (Protected Designation of Origin Made in Italy, Made in Italy, Italian Sounding, and Generic Foreign). Main hypotheses are tested via a survey with the specific product images administered to samples in Italy (N = 204, 148 Italians and 56 non-Italians), China (N = 191, 100 Chinese and 91 non-Italian expatriates in China), and the USA (N = 237 US citizens). Across the three studies, results show that Made in Italy products, compared to the other ones, are advantaged in terms of the main dependent variables: reputation profile, general reputation, attitude, and willingness to pay (WTP). Moreover, Italian Sounding products are endowed with corresponding significant advantages when compared to the Generic Foreign by non-Italian samples (although to a different degree according to the different sub-samples). Results reveal the specific social–psychological profile of Italian Sounding products in terms of either weaknesses or strengths when compared to both Made in Italy products and Generic Foreign ones, differently in the eyes of Italian and non-Italian consumers across different countries. Finally, consistently across the three studies, the extent to which a food product is perceived to be Italian increases consumers' WTP for that product, and this effect is consistently mediated by the product's reputation

Food Reputation and Food Preferences: Application of the Food Reputation Map (FRM) in Italy, USA, and China

Given the food challenges that society is facing, we draw upon recent developments in the study of how food reputation affects food preferences and food choices, providing here a starting standard point for measuring every aspect of food reputation in different cultural contexts across the world. Specifically, while previous attempts focused either on specific aspects of food or on measures of food features validated in one language only, the present research validates the Food Reputation Map (FRM) in Italian, English and Chinese over 2,250 participants worldwide. Here we successfully measure food reputation across 23 specific indicators, further grouped into six synthetic indicators of food reputation. Critically, results show that: (a) the specific measurement tool of food reputation can vary across cultural contexts, and that (b) people's reputation of food products or categories changes significantly across different cultural contexts. Therefore, in order to understand people's food preferences and consumption, it is important to take into account the repertoire of cultural differences that underlies the contexts of analysis: the three context-specific versions of the FRM presented here effectively deal with this issue and provide reliable context-specific insights on stakeholders' interests, perspectives, attitudes and behaviors related to food perceptions, assessment, and consumption, which can be effectively leveraged to foster food sustainability