2,197 research outputs found
Symmetry in Full Counting Statistics, Fluctuation Theorem, and Relations among Nonlinear Transport Coefficients in the Presence of a Magnetic Field
We study full counting statistics of coherent electron transport through
multi-terminal interacting quantum-dots under a finite magnetic field.
Microscopic reversibility leads to the symmetry of the cumulant generating
function, which generalizes the fluctuation theorem in the context of quantum
transport. Using this symmetry, we derive the Onsager-Casimir relation in the
linear transport regime and universal relations among nonlinear transport
coefficients.Comment: 4.1pages, 1 figur
Kinetics and thermodynamics of first-order Markov chain copolymerization
We report a theoretical study of stochastic processes modeling the growth of
first-order Markov copolymers, as well as the reversed reaction of
depolymerization. These processes are ruled by kinetic equations describing
both the attachment and detachment of monomers. Exact solutions are obtained
for these kinetic equations in the steady regimes of multicomponent
copolymerization and depolymerization. Thermodynamic equilibrium is identified
as the state at which the growth velocity is vanishing on average and where
detailed balance is satisfied. Away from equilibrium, the analytical expression
of the thermodynamic entropy production is deduced in terms of the Shannon
disorder per monomer in the copolymer sequence. The Mayo-Lewis equation is
recovered in the fully irreversible growth regime. The theory also applies to
Bernoullian chains in the case where the attachment and detachment rates only
depend on the reacting monomer
The micro-optical ring electrode Part 2 : theory for the transport limited, steady-state photocurrent.
The micro-optical ring electrode (MORE) is a photoelectrochemical device based on a ring microelectrode that uses the insulating material interior to the ring electrode as a light guide. In this paper, we derive asymptotic analytical expressions for the steady-state, transport limited photocurrent generated at MOREs with thin microrings ((ring inner radius)/(ring outer radius) values > 0.99) for two general types of photoelectrochemical system (a) the PE (photophysical-electrochemical) system, wherein the photoexcited species itself is directly detected on the ring; and (b) the PCE (photophysical-chemical-electrochemical) system, wherein the photoexcited species undergoes a homogeneous electron transfer reaction prior to electrochemical detection. The expressions are generated by exploiting the properties of discontinuous integrals of Bessel functions to solve the diffusion equation for the photogenerated electroactive species both inside and outside the beam. The resultant solutions are then matched at the beam surface. The expressions themselves are used to design experimental protocols that allow for the complete characterization of the photoelectrochemical kinetics of a system and are tested by using them to interpret the results of a MORE study of the photoelectrochemical behaviour of the Ru(bipy)(3)(2+)/Fe3+ photosensitiser/ quenching agent system. The value of the Stern-Volmer constant for the quenching of photoexcited Ru(bipy)(3)(2+) by Fe obtained (0.36 m(3) mol(-1)) compares favourably with the value obtained from fluorescence measurements (0.9 m(3) mol(-1)). (c) 2006 Elsevier B.V. All rights reserved
Microscopic reversibility of quantum open systems
The transition probability for time-dependent unitary evolution is invariant
under the reversal of protocols just as in the classical Liouvillian dynamics.
In this article, we generalize the expression of microscopic reversibility to
externally perturbed large quantum open systems. The time-dependent external
perturbation acts on the subsystem during a transient duration, and
subsequently the perturbation is switched off so that the total system would
thermalize. We concern with the transition probability for the subsystem
between the initial and final eigenstates of the subsystem. In the course of
time evolution, the energy is irreversibly exchanged between the subsystem and
reservoir. The time reversed probability is given by the reversal of the
protocol and the initial ensemble. Microscopic reversibility equates the time
forward and reversed probabilities, and therefore appears as a thermodynamic
symmetry for open quantum systems.Comment: numerical demonstration is correcte
Thermodynamic time asymmetry in nonequilibrium fluctuations
We here present the complete analysis of experiments on driven Brownian
motion and electric noise in a circuit, showing that thermodynamic entropy
production can be related to the breaking of time-reversal symmetry in the
statistical description of these nonequilibrium systems. The symmetry breaking
can be expressed in terms of dynamical entropies per unit time, one for the
forward process and the other for the time-reversed process. These entropies
per unit time characterize dynamical randomness, i.e., temporal disorder, in
time series of the nonequilibrium fluctuations. Their difference gives the
well-known thermodynamic entropy production, which thus finds its origin in the
time asymmetry of dynamical randomness, alias temporal disorder, in systems
driven out of equilibrium.Comment: to be published in : Journal of Statistical Mechanics: theory and
experimen
Fluctuation theorem for entropy production during effusion of a relativistic ideal gas
The probability distribution of the entropy production for the effusion of a
relativistic ideal gas is calculated explicitly. This result is then extended
to include particle and anti-particle pair production and annihilation. In both
cases, the fluctuation theorem is verified.Comment: 6 pages, no figure
Stochastic thermodynamics of chemical reaction networks
For chemical reaction networks described by a master equation, we define
energy and entropy on a stochastic trajectory and develop a consistent
nonequilibrium thermodynamic description along a single stochastic trajectory
of reaction events. A first-law like energy balance relates internal energy,
applied (chemical) work and dissipated heat for every single reaction. Entropy
production along a single trajectory involves a sum over changes in the entropy
of the network itself and the entropy of the medium. The latter is given by the
exchanged heat identified through the first law. Total entropy production is
constrained by an integral fluctuation theorem for networks arbitrarily driven
by time-dependent rates and a detailed fluctuation theorem for networks in the
steady state. Further exact relations like a generalized Jarzynski relation and
a generalized Clausius inequality are discussed. We illustrate these results
for a three-species cyclic reaction network which exhibits nonequilibrium
steady states as well as transitions between different steady states.Comment: 14 pages, 2 figures, accepted for publication in J. Chem. Phy
Fluctuation theorem for currents in open quantum systems
A quantum-mechanical framework is set up to describe the full counting
statistics of particles flowing between reservoirs in an open system under
time-dependent driving. A symmetry relation is obtained which is the
consequence of microreversibility for the probability of the nonequilibrium
work and the transfer of particles and energy between the reservoirs. In some
appropriate long-time limit, the symmetry relation leads to a steady-state
quantum fluctuation theorem for the currents between the reservoirs. On this
basis, relationships are deduced which extend the Onsager-Casimir reciprocity
relations to the nonlinear response coefficients.Comment: 19 page
Single electron transistor strongly coupled to vibrations: Counting Statistics and Fluctuation Theorem
Using a simple quantum master equation approach, we calculate the Full
Counting Statistics of a single electron transistor strongly coupled to
vibrations. The Full Counting Statistics contains both the statistics of
integrated particle and energy currents associated to the transferred electrons
and phonons. A universal as well as an effective fluctuation theorem are
derived for the general case where the various reservoir temperatures and
chemical potentials are different. The first relates to the entropy production
generated in the junction while the second reveals internal information of the
system. The model recovers Franck-Condon blockade and potential applications to
non-invasive molecular spectroscopy are discussed.Comment: extended discussion, to appear in NJ
Universal Properties of Nonlinear Response Functions of Nonequilibrium Steady States
We derive universal properties of nonlinear response functions of
nonequilibrium steady states. In particular, sum rules and asymptotic behaviors
are derived. Their consequences are illustrated for nonlinear optical materials
and nonlinear electrical conductors.Comment: 10 pages, 1 figure; added a few sentences and references to explain
detail
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