169,165 research outputs found
Mott physics in electron dioxygenyl magnet : OF (=Sb, Pt)
We have investigated electronic structures and magnetic properties of
OF (=Sb, Pt), which are composed of two building blocks of
strongly correlated electrons: O dioxygenyls and F
octahedra, by employing the first-principles electronic structure band method.
For OSbF, as a reference system of OPtF, we have shown
that the Coulomb correlation of O(2) electrons drives the Mott insulating
state. For OPtF, we have demonstrated that the Mott insulating
state is induced by the combined effects of the Coulomb correlation of O(2)
and Pt(5) electrons and the spin-orbit (SO) interaction of Pt(5) states.
The role of the SO interaction in forming the Mott insulating state of
OPtF is similar to the case of SrIrO that is a
prototype of a SO induced Mott system with J.Comment: 5 pages, 6 figure
Evaluation of stochastic effects on biomolecular networks using the generalised Nyquist stability criterion
Abstract—Stochastic differential equations are now commonly used to model biomolecular networks in systems biology, and much recent research has been devoted to the development of methods to analyse their stability properties. Stability analysis of such systems may be performed using the Laplace transform, which requires the calculation of the exponential
matrix involving time symbolically. However, the calculation of the symbolic exponential matrix is not feasible for problems of even moderate size, as the required computation time increases exponentially with the
matrix order. To address this issue, we present a novel method for approximating the Laplace transform which does not require the exponential matrix to be calculated explicitly. The calculation time associated with
the proposed method does not increase exponentially with the size of the system, and the approximation error is shown to be of the same order as existing methods. Using this approximation method, we show how a straightforward application of the generalized Nyquist stability criterion
provides necessary and sufficient conditions for the stability of stochastic biomolecular networks. The usefulness and computational efficiency of the proposed method is illustrated through its application to the problem of analysing a model for limit-cycle oscillations in cAMP during aggregation of Dictyostelium cells
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