Berlin 2005 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 13: Quantum Chaos

DY 13.3: Vortrag

Freitag, 4. März 2005, 14:45–15:00, TU H2032

Resonance-and chaos-assisted tunneling in mixed regular-chaotic systems — •Christopher Eltschka and Peter Schlagheck — Institut f. Theoretische Physik, Universität Regensburg

Despite its genuine quantal character, dynamical tunneling is strongly sensitive to details of the underlying classical phase space. A particularly prominent scenario in this context is “chaos-assisted” tunneling which takes place between quantum states that are localized on two symmetry-related islands in a mixed regular-chaotic phase space. We present evidence that nonlinear resonances govern this tunneling process. In a similar way as for near-integrable tunneling, such resonances induce couplings between regular states within the island and states that are supported by the chaotic sea. On the basis of this mechanism, we derive a semiclassical expression for the average tunneling rate, which yields good agreement in comparison with the exact quantum tunneling rates calculated for the kicked rotor and the kicked Harper.