975 research outputs found
Analytic Approach for Controlling Realistic Quantum Chaotic Systems
An analytic approach for controlling quantum states, which was originally
applied to fully random matrix systems [T. Takami and H. Fujisaki, Phys. Rev. E
75, 036219 (2007)], is extended to deal with more realistic quantum systems
with a banded random matrix (BRM). The validity of the new analytic field is
confirmed by directly solving the Schroedinger equation with a BRM interaction.
We find a threshold of the width of the BRM for the quantum control to be
successful.Comment: 4 pages with 4 PostScript figures, to appear in the Proceedings of
ICCMSE 2007 in a section of Symposium 8 "Quantum Control and Light-Matter
Interactions: Recent Computational and Theoretical Results
Time-dependent perturbation theory for vibrational energy relaxation and dephasing in peptides and proteins
Without invoking the Markov approximation, we derive formulas for vibrational
energy relaxation (VER) and dephasing for an anharmonic system oscillator using
a time-dependent perturbation theory. The system-bath Hamiltonian contains more
than the third order coupling terms since we take a normal mode picture as a
zeroth order approximation. When we invoke the Markov approximation, our theory
reduces to the Maradudin-Fein formula which is used to describe VER properties
of glass and proteins. When the system anharmonicity and the renormalization
effect due to the environment vanishes, our formulas reduce to those derived by
Mikami and Okazaki invoking the path-integral influence functional method [J.
Chem. Phys. 121 (2004) 10052]. We apply our formulas to VER of the amide I mode
of a small amino-acide like molecule, N-methylacetamide, in heavy water.Comment: 16 pages, 5 figures, 5 tables, submitted to J. Chem. Phy
Robust Consensus of Second-Order Heterogeneous Multi-Agent Systems via Dynamic Interaction
A consensus problem is proposed for second-order multi-agent systems with heterogeneous mass distribution. The motivation of this work is mainly related to spacecraft attitude coordinated control, in which gyroless configuration is considered, to avoid drift errors and design of estimation filters. The considered spacecraft includes flexible modes and coupling between the rigid and flexible dynamics. Dynamic interaction between the agents is considered. Moreover, the achievement of the consensus and robust stabilization are shown for coordinated heterogeneous multi-agent systems, for undirected and connected graph topology. Finally, the effectiveness of the proposed controller is shown for a precise pointing mission of the Crab Nebula
Bosonic D-branes at finite temperature with an external field
Bosonic boundary states at finite temperature are constructed as solutions of
boundary conditions at for bosonic open strings with a constant gauge
field coupled to the boundary. The construction is done in the
framework of thermo field dynamics where a thermal Bogoliubov transformation
maps states and operators to finite temperature. Boundary states are given in
terms of states from the direct product space between the Fock space of the
closed string and another identical copy of it. By analogy with zero
temperature, the boundary states heve the interpretation of -brane at
finite temperature. The boundary conditions admit two different solutions. The
entropy of the closed string in a -brane state is computed and analysed. It
is interpreted as the entropy of the -brane at finite temperature.Comment: 21 pages, Latex, revised version with minor corrections and
references added, to be published in Phys. Rev.
Boneh-Franklin Identity Based Encryption Revisited
Contains fulltext :
33216.pdf (preprint version ) (Open Access
- …