1,721,256 research outputs found
Straight-line motion of classical point particles in a three-dimensional lattice
No full textBy means of the usual definition of inner product and of the Gauss condition on the sum of squares of three integers in number theory, it can be seen that there exist specific directions in continuous space in which a classical point particle moving in a three-dimensional lattice cannot propagate. When representing all directions for which propagation is possible as points on a unitary sphere, the forbidden directions appear as vacancies on this sphere. By means of a stereographic projection of the allowed direction, it is argued that propagation is not allowed for specific sets of points on the stereographic plane. The present work can be considered as an interdisciplinary lecture for advanced high-school students or to first-year college students
Irreversible magnetic response of an elementary three-dimensional model for granular superconductors
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Ratchet potential in superconducting quantum interference devices containing a double-barrier junction
No full textLorentz force on sodium and chlorine ions in salt water flow under a transverse magnetic field: an alternative power generation option
No full textInterferenza quantistica in dispositivi superconduttivi
No full textFenomeni analoghi all'interferenza in ottica fisica sono osservabili in dispositivi superconduttivi contenenti giunzioni Josephson. Lo SQUID ( "Superconducting QUantum Interference Device") è uno di questi sistemi. Partendo dalle equazioni di Josephson per i sistemi superconduttivi debolmente accoppiati, opereremo un parallelo tra i fenomeni di interferenza in ottica e quelli osservati in superconduttività. In particolare, vedremo che la figura ottica di interferenza ottenuta da sue fenditure è simile alla dipendenza dal campo magnetico del quadrato della corrente critica del dispositivo superconduttivo.Infine, prendendo in considerazione anche fenomeni di diffrazione, noteremo importanti differenze, tra il sistema e quello superconduttivo, ascrivibili alla coerenza quantistica di quest'ultimo
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