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Ginzburg-Landau theory and Josephson eect in BCS-BEC crossover
The thesis analyze Fermionic neutral systems with tunable attractive interaction between the particles whose strenght can be tuned from BCS theory to Bose-Einstein condensate. Below the critical temperature both systems are characterized by an order parameter. A mean-field approach can't describe correctly the phenomenon. This happens if Gaussian Thermal fluctations are included. The aim is to study BCS-BEC crossover around critical temperature through Ginzburg-Landau theory in 3D systems and Josephson effect in 2D systems. In both cases effect of thermal fluctuations have been included
Optimal Control of two-level quantum systems via Chopped RAndom Basis algorithm
This work is devoted to the study and the application of the Chopped RAndomBasis (CRAB) control algorithm as an efficient, versatile optimal control techniqueto be used for the purpose of enhancing the quality of quantum processes. In orderto show its principal aspects, the method is here applied to different systems, inparticular one-qubit and two-qubit system. Finally, the dressed CRAB algorithmis presented as a valid alternative to the standard method, as it comes with theadditional property of guaranteed convergence to the global optimu
L'effetto Cerenkov
L'effetto Cerenkov è un fenomeno consistente nell'emissione di radiazione elettromagnetica da parte di un mezzo dielettrico, nel particolare caso in cui questo è attraversato da una particella carica in modo rettilineo uniforme con una velocità maggiore della velocità della luce nel mezzo. La tesi ripercorre l'interpretazione teorica dell'effetto fornita dai fisici Frank e Tamm nell'ambito dell'elettrodinamica classica, la quale si basa sulla risoluzione dell'equazione di Maxwell in un mezzo dispersivo