TY  - GEN
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/10176/
KW  - Fermi-Beschleunigung 
KW  -  Getriebene Systeme 
KW  -  Anomale DiffusionBilliards 
KW  -  Driven systems 
KW  -  Fermi-acceleration
KW  -  anomalous diffusion 
KW  -  deterministic chaos
Y1  - 2009///
A1  - Lenz, Florian
AV  - public
ID  - heidok10176
TI  - Classical and quantum dynamics of driven elliptical billiards
N2  - Subject of this thesis is the investigation of the classical dynamics of the driven elliptical billiard and the development of a numerical method allowing the propagation of arbitrary initial states in the quantum version of the system. In the classical case, we demonstrate that there is Fermi acceleration in the driven billiard. The corresponding transport process in momentum space shows a surprising crossover from sub- to normal diffusion. This crossover is not parameter induced, but rather occurs dynamically in the evolution of the ensemble. The four-dimensional phase space is analyzed in depth, especially how its composition changes in different velocity regimes. We will show  that the stickiness properties, which eventually determine the diffusion, are intimately connected with this change of the composition of the phase space with respect to velocity. In the course of the evolution, the accelerating ensemble thus explores regions of varying stickiness, leading to the mentioned crossover in the diffusion. In the quantum case, a series of transformations tailored to the elliptical billiard is applied to circumvent the time-dependent Dirichlet boundary conditions. By means of an expansion ansatz, this eventually yields a large system of coupled ordinary differential equations, which can be solved by standard techniques.
ER  -