Photon correlations in the collective emission of hybrid gold-(CdSe/CdS/CdZnS) nanocrystal supraparticles

We investigate the photon statistics of the light emitted by single self-assembled hybrid gold-CdSe/CdS/CdZnS colloidal nanocrystal supraparticles through the detailed analysis of the intensity autocorrelation function $g^{(2)}(\tau)$. We first reveal that, despite the large number of nanocrystals involved in the supraparticle emission, antibunching can be observed. We then present a model based on non-coherent F\"orster energy transfer and Auger recombination that well captures photon antibunching. Finally, we demonstrate that some supraparticles exhibit a bunching effect at short time scales corresponding to coherent collective emission

Technological disruptions in services: lessons from tourism and hospitality

Purpose: Technological disruptions such as the Internet of Things and autonomous devices, enhanced analytical capabilities (artificial intelligence) and rich media (virtual and augmented reality) are creating smart environments that are transforming industry structures, processes and practices. The purpose of this paper is to explore critical technological advancements using a value co-creation lens to provide insights into service innovations that impact ecosystems. The paper provides examples from tourism and hospitality industries as an information dependent service management context. Design/methodology/approach: The research synthesizes prevailing theories of co-creation, service ecosystems, networks and technology disruption with emerging technological developments. Findings: Findings highlight the need for research into service innovations in the tourism and hospitality sector at both macro-market and micro-firm levels, emanating from the rapid and radical nature of technological advancements. Specifically, the paper identifies three areas of likely future disruption in service experiences that may benefit from immediate attention: extra-sensory experiences, hyper-personalized experiences and beyond-automation experiences. Research limitations/implications: Tourism and hospitality services prevail under varying levels of infrastructure, organization and cultural constraints. This paper provides an overview of potential disruptions and developments and does not delve into individual destination types and settings. This will require future work that conceptualizes and examines how stakeholders may adapt within specific contexts. Social implications: Technological disruptions impact all facets of life. A comprehensive picture of developments here provides policymakers with nuanced perspectives to better prepare for impending change. Originality/value: Guest experiences in tourism and hospitality by definition take place in hostile environments that are outside the safety and familiarity of one’s own surroundings. The emergence of smart environments will redefine how customers navigate their experiences. At a conceptual level, this requires a complete rethink of how stakeholders should leverage technologies, engage and reengineer services to remain competitive. The paper illustrates how technology disrupts industry structures and stimulates value co-creation at the micro and macro-societal level

Island diffusion on metal fcc(100) surfaces

We present Monte Carlo simulations for the size and temperature dependence of the diffusion coefficient of adatom islands on the Cu(100) surface. We show that the scaling exponent for the size dependence is not a constant but a decreasing function of the island size and approaches unity for very large islands. This is due to a crossover from periphery dominated mass transport to a regime where vacancies diffuse inside the island. The effective scaling exponents are in good agreement with theory and experiments.Comment: 13 pages, 2 figures, to be published in Phys. Rev. Let

A contiuum model for low temperature relaxation of crystal steps

High and low temperature relaxation of crystal steps are described in a unified picture, using a continuum model based on a modified expression of the step free energy. Results are in agreement with experiments and Monte Carlo simulations of step fluctuations and monolayer cluster diffusion and relaxation. In an extended model where mass exchange with neighboring terraces is allowed, step transparency and a low temperature regime for unstable step meandering are found.Comment: Submitted to Phys.Rev.Let

The effects of early leaf removal and cluster thinning treatments on berry growth and grape composition in cultivars Vranac and Cabernet Sauvignon

Background: The aim of the present work was to investigate the effect of early leaf removal and cluster thinning treatments in the Mediterranean climate on berry growth and how these two techniques affect phenolic profile (especially proathocyanidins) and color characteristics for later wine production. The study was conducted in 2011 in Podgorica, Montenegro. Two grapevine cultivars were selected to compare different ability in flavonoid accumulation: Vranac, with moderate accumulation and Cabernet Sauvignon, usually showing very good accumulation of polyphenols. Four treatments were compared: only leaf removal, only cluster thinning, leaf removal combined with cluster thinning, and no treatment that was used for control (control set). Results: Early defoliation reduced the yield in both varieties. In Cabernet Sauvignon, defoliation initially delayed berry growth, but at the end, defoliation slightly affected almost all yield parameters (cluster weight, berry weight, and number of berries per cluster), while in cultivar Vranac, defoliation did not modify the berry growth and berry weight. In both varieties, cluster thinning did not affect the berry weight. In the treatments where both defoliation and cluster thinning was applied, a reduction of the cluster weight, berry weight, and berry numbers per cluster was observed. Cabernet Sauvignon showed a greater reactivity to the applied techniques, while Vranac was less reactive. At harvest, no damaged bunches (caused by sunburn) were found in defoliated treatment. Conclusions: It can be concluded that for both varieties, early defoliation and cluster thinning lead to better soluble solids accumulation than in the control set. The treatments lead to raised concentration of anthocyanins and proanthocyanidins in both varieties. It is confirmed that the highest content of anthocyanins and proanthocyanidins was in the skin extracts of the grapes where both treatments were applied. This is followed by the treatment where only defoliation was applied. The enhanced contents of these compounds per berry in grape variety Vranac are the result of increased synthesis, while in Cabernet sauvignon variety, increased content was due to the less berry weight. The best wine characteristics (alcohol, color intensity, color hue, total anthocyanins, total polyphenols) were found in products, where defoliation was applied

Growth of nanostructures by cluster deposition : a review

This paper presents a comprehensive analysis of simple models useful to analyze the growth of nanostructures obtained by cluster deposition. After detailing the potential interest of nanostructures, I extensively study the first stages of growth (the submonolayer regime) by kinetic Monte-Carlo simulations. These simulations are performed in a wide variety of experimental situations : complete condensation, growth with reevaporation, nucleation on defects, total or null cluster-cluster coalescence... The main scope of the paper is to help experimentalists analyzing their data to deduce which of those processes are important and to quantify them. A software including all these simulation programs is available at no cost on request to the author. I carefully discuss experiments of growth from cluster beams and show how the mobility of the clusters on the surface can be measured : surprisingly high values are found. An important issue for future technological applications of cluster deposition is the relation between the size of the incident clusters and the size of the islands obtained on the substrate. An approximate formula which gives the ratio of the two sizes as a function of the melting temperature of the material deposited is given. Finally, I study the atomic mechanisms which can explain the diffusion of the clusters on a substrate and the result of their mutual interaction (simple juxtaposition, partial or total coalescence...)Comment: To be published Rev Mod Phys, Oct 99, RevTeX, 37 figure