Driven Tunneling: Chaos and Decoherence

Chaotic tunneling in a driven double-well system is investigated in absence as well as in the presence of dissipation. As the constitutive mechanism of chaos-assisted tunneling, we focus on the dynamics in the vicinity of three-level crossings in the quasienergy spectrum. The coherent quantum dynamics near the crossing is described satisfactorily by a three-state model. It fails, however, for the corresponding dissipative dynamics, because incoherent transitions due to the interaction with the environment indirectly couple the three states in the crossing to the remaining quasienergy states. The asymptotic state of the driven dissipative quantum dynamics partially resembles the, possibly strange, attractor of the corresponding damped driven classical dynamics, but also exhibits characteristic quantum effects.Comment: 32 pages, 35 figures, lamuphys.st

The Centre for Development and Environment (CDE), University of Bern

The Centre for Development and Environment (CDE) is the University of Bern's center for sustainable development research. Founded in 1988 as a part of the Institute of Geography, CDE became an interdisciplinary university center in 2009. Its current overall aim is to foster sustainable development-oriented research across various institutes and departments of the University of Bern. In view of this new mandate, CDE devised a new strategy focusing on 6 strategic themes. These are explored and advanced by groups of researchers organized in thematic clusters. Three of the 6 clusters address sustainable development from a comprehensive perspective: global change impacts, innovations for sustainable development, and education for sustainable development. These clusters are complemented by 3 clusters that investigate sustainable development with a specialized perspective: natural resources and ecosystem services, multidimensional disparities, and governance of land and natural resources

Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential

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Exact Fidelity and Full Fidelity Statistics in Regular and Chaotic Surroundings

For a prepared state exact expressions for the time dependent mean fidelity as well as for the mean inverse paricipation ratio are obtained analytically. The distribution function of fidelity in the long time limit and of inverse participation ratio are studied numerically and analytically. Surprising features like fidelity revival and enhanced non--ergodicity are observed. The role of the coupling coefficients and of complexity of background is studied as well.Comment: 4 pages 3 figure