Quantum effects of electric fields and potentials on electron motion: an introduction to theoretical and practical aspects

In the so-called electric Aharonov-Bohm effect, a quantum interference pattern shift is produced when electrons move in an electric field-free region but, at the same time, under the presence of a time-dependent electric potential. Analogous fringe shifts are observed in interference experiments where electrons, travelling through an electrostatic field, suffer a classical lag effect produced by electric forces. Since these experiments are reported mainly in specialized journals, it could be rather difficult and time consuming for a student to attain a comprehensive overview of the subject. Therefore, particular attention has been addressed to reviewing the theory, to describing a couple of experiments and to the interpretation of the results. We believe that students can be suitably introduced to exploring the \u201cparadoxical\u201d aspects of the interaction of electrons with electric potentials and fields

An experiment on the particle-wave nature of electrons

A primary electron beam of a transmission electron microscope is scattered into secondary beams by the planes of atoms of a single crystal. These secondary beams are focused to form a diffraction pattern in the final screen. This experiment is similar to the Thompson one which, independently by Davisson and Germer, demonstrated the De Broglie hypothesis of the existence of electron waves. Without changing the experimental apparatus, it is possible to realize an interference experiment with electrons coming from two spatially separated sources in analogy with the optical Young set-up. Both experiments are a clear evidence of the electron wave-like behaviour. By varying the conditions of illumination, changes of the fringe visibility which reveal the spatial coherence properties of the electron beam are displayed

Notebook 2015

\ufeff\ufeff\ufeff\ufeff\ufeffThe first \u201cNotebook of Cultures, Fashion and Society\u201d contains some monographic essays (reflections on aesthetics, phenomenology and research between art and fashion) and a collection of contributions on the relationship between Fashion and Creativity. The initial monographic essay by Giovanni Matteucci, Simmel on Fashion, is an original philosophical reinterpretation of the famous contribution on fashion offered in its accomplished final version of 1911 by the German scholar. Such version (not available in English yet) is thoroughly examined by Giovanni Matteucci - scholar of Aesthetics at the University of Bologna - who, among other interesting observations, questions the widespread interpretation of Simmel as advocate of the well-known \u201ctrickle-down\u201d phenomenon in the diffusion of fashion. Matteucci, instead, proposes a fresh interpretation of Simmel\u2019s thought based on fashion as a valued model of a special form of life, a paradigm of the constitution of social groups, which establish social relationships especially in the new metropolitan society that often break free from deep rooted contents. Hence the various implications of the phenomenon of fashion, in the creation of identity and permeating function of the aesthetic, make careful reading of Simmel\u2019s essay still useful. Federica Muzzarelli\u2019s critical essay, From Family Album to Snapshot Style, starts with the analysis of the primary role of memory and links up mechanisms both in the identity of photographic sign, and artistic operations that use photography. Muzzarelli, a scholar of Photography Theory, starts from a reflection of the meaning and the role of time in pioneering experiences while using photographic means. She investigates some social practices (the amateur use of the camera during the Kodak era and family albums) in order to find in them the necessary introduction for the explosion in the XXth Century of the cultured and conceptual phenomena of art and fashion. The essay Antagonistic Fashion. The Last Generations after Japanese Post-atomic Wave, by a young scholar of the University of Bologna - Chiara Pompa - deals with the latest radical trends and current inclinations labelled as anti-pop, anti-form, anti-glam, in a word, anti-fashion. The prefix \u201canti\u201d is to be intended as a banner of contrast and opposition in respect to mainstream fashion canons. Drawing from a methodological frame rooted in the phenomenology of styles, from which she borrows a historical-critical structure usually applied to the arts, Pompa marks the trends of some designers\u2019 latest generations (such as Carol Christian Poell, Maurizio Altieri and Rick Owens) who are on the same wavelength as that of the research started by Yohji Yamamoto, Rei Kawakubo and Issey Miyake. Finally, the essay collection entitled Fashion and Creativity originates from a topic of the Summer School that took place in June 2014 at Zonemoda - University of Bologna - Rimini Campus. On that occasion, some of the most important international fashion scholars (on the basis of their different study perspectives and methodologies) faced the theme of relationships between the mechanism of creativity and the economic-cultural fashion system. This was crucial but hard to classify. Giovanni Emanuele Corazza (life and soul of the Marconi Institute for Creativity, - University of Bologna - where he works with his partners Sergio Agnoli e Sara Martello) proposes a vision of the creative process that is transversal and particular in that field. Then he embeds it in the specificity of Fashion Design which is characterized by the multi-level definition of clients\u2019 needs as well as by special parameters to determine a product\u2019s success during a particular season. Nathalie Khan, who teaches fashion history and theory at Central Saint Martins and London College of Fashion, investigated the relationship between Pierre Debusschere\u2019s artistic production, fashion films, \u201cDazed&Confused\u201d editorials, and the transposition in images of Martin Margiela the creative genius. Yuniya Kawamura - Fashion scholar and sociologist at the Fashion Institute of Technology - New York - studied in depth the reception and construction of creativity notions in fashion from a sociologic point of view