4,807 research outputs found
Nonequilibrium stochastic processes: Time dependence of entropy flux and entropy production
Based on the Fokker-Planck and the entropy balance equations we have studied
the relaxation of a dissipative dynamical system driven by external
Ornstein-Uhlenbeck noise processes in absence and presence of nonequilibrium
constraint in terms of the thermodynamically inspired quantities like entropy
flux and entropy production. The interplay of nonequilibrium constraint,
dissipation and noise reveals some interesting extremal nature in the time
dependence of entropy flux and entropy production.Comment: RevTex, 17 pages, 9 figures. To appear in Phys. Rev.
Distributing Awards Efficiently: More on King Solomon's Problem
We consider a multi-award generalisation of King Solomon's problem: k identical and indivisible awards should be distributed among agents, k 1) prizes efficiently in sub-game perfect equilibria without any monetary transfers in equilibrium. Finally, in the multi-awards case we relax the complete information assumption and achieve implementation of efficient allocation by iterative elimination of weakly dominated strategies, using generalisation of Olszewski's (2003) mechanism
Ultrahigh Charge Carrier Mobility in Nanotube Encapsulated Coronene Stack
Achieving high charge carrier mobility is the holy grail of organic
electronics. In this letter we report a record charge carrier mobility of 14.93
cm Vs through a coronene stack encapsulated in a single
walled carbon nanotube (CNT) by using a multiscale modeling technique which
combines MD simulations, first principle calculations and Kinetic Monte Carlo
simulations. For the CNT having a diameter of 1.56 nm we find a highly ordered
defect free organization of coronene molecules inside the CNT which is
responsible for the high charge carrier mobility. The encapsulated coronene
molecules are correlated with a large correlation length of 18 {\AA}
which is independent of the length of the coronene column. Our simulation
further suggests that coronene molecules can spontaneously enter the CNT,
suggesting that the encapsulation is experimentally realizable
Universality in Intensity Modulated Photocurrent in Bulk-Heterojunction Polymer Solar Cells
We observe a universal feature in the frequency dependence of intensity
modulated photocurrent Iph based on studies of a variety of efficient
bulk-heterojunction polymer solar cells (BHJ-PSCs). This feature of Iph appears
in the form of a local maximum in the 5 kHz < frequency < 10 kHz range and is
observed to be largely independent of the external parameters such as modulated
light intensity (Lac), wavelength, temperature (T), and external field (EF)
over a wide range. Simplistic kinetic models involving carrier generation,
recombination and extraction processes are used to interpret the overall
essential features of Iph and correlate it to the device parameters
Quantum noise-induced chaotic oscillations
We examine the weak quantum noise limit of Wigner equation for phase space
distribution functions. It has been shown that the leading order quantum noise
described in terms of an auxiliary Hamiltonian manifests itself as an
additional fluctuational degree of freedom which may induce chaotic and regular
oscillations in a nonlinear oscillator.Comment: minor corrections, new references adde
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