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The influence of periodic driving on coherent tunneling is investigated, using a quartic double-well potential in a monochromatic external field as a working example. Extensive numerical studies of the long-time behaviour of this system are combined with an analytical description on basis of the quasienergy formalism. Approximate solutions of the dynamics(More)
Using the parametrically driven harmonic oscillator as a working example, we study two different Markov-ian approaches to the quantum dynamics of a periodically driven system with dissipation. In the simpler approach, the driving enters the master equation for the reduced density operator only in the Hamiltonian term. An improved master equation is achieved(More)
We study the interplay between coherent transport by tunneling and diffusive transport through classically chaotic phase-space regions, as it is reflected in the Floquet spectrum of the periodically driven quartic double well. The tunnel splittings in the semiclassical regime are determined with high numerical accuracy, and the association of the(More)
  • Thomas Dittrich, Chen Menachem, Herzel Yamin, Lou Adams, Tadiran Batteries
  • 2011
Non-rechargeable batteries with a life of 20 years and more are required today for many smart metering and AMR applications in the US. Tadiran's non-rechargeable lithium thionyl chloride batteries offer a proven life of 25 years. Kohler's new touchless commercial faucet was designed to run even 30 years on a hybrid lithium battery. Similar requirements(More)
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. They are formed when a tunnel doublet, located on a pair of symmetry-related tori in(More)
We consider a quasi one-dimensional chain of N chaotic scattering elements with periodic boundary conditions. The classical dynamics of this system is dominated by diffusion. The quantum theory, on the other hand, depends crucially on whether the chain is disordered or invariant under lattice translations. In the disordered case, the spectrum is dominated(More)
The quantum dynamics of a quartic double well, subjected to a harmonically oscillating field, is studied in the framework of the Floquet formalism. The modifications of the familiar tunneling process due to the driving are investigated numerically and explained in terms of the structure of the corresponding local quasienergy spectrum. In particular, there(More)
Evolutionary Algorithms are metaheuristic optimization algorithms which are based on a population of individual candidate solutions. These solutions are evolved with the aim to solve a given problem. We compare two types of Evolutionary Algorithms, one with a panmictic population and one with a spatially-structured population. Previous works indicate that(More)