2,160 research outputs found
Quantum work relations and response theory
A universal quantum work relation is proved for isolated time-dependent
Hamiltonian systems in a magnetic field as the consequence of
microreversibility. This relation involves a functional of an arbitrary
observable. The quantum Jarzynski equality is recovered in the case this
observable vanishes. The Green-Kubo formula and the Casimir-Onsager reciprocity
relations are deduced thereof in the linear response regime
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
Modified Fluctuation-dissipation theorem for non-equilibrium steady-states and applications to molecular motors
We present a theoretical framework to understand a modified
fluctuation-dissipation theorem valid for systems close to non-equilibrium
steady-states and obeying markovian dynamics. We discuss the interpretation of
this result in terms of trajectory entropy excess. The framework is illustrated
on a simple pedagogical example of a molecular motor. We also derive in this
context generalized Green-Kubo relations similar to the ones derived recently
by Seifert., Phys. Rev. Lett., 104, 138101 (2010) for more general networks of
biomolecular states.Comment: 6 pages, 2 figures, submitted in EP
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
Les structures synsédimentaires miocènes en compression associées au décrochement dextre Mhrila-Chérichira (Tunisie centrale)
L'étude de l'accident tectonique Mhrila-Chérichira (Tunisie centrale) met en évidence la permanence de son activité depuis le Crétacé inférieur jusqu'au Villafranchien et permet de retracer l'évolution tectonique de cette région
Fluctuation theorem for the effusion of an ideal gas
The probability distribution of the entropy production for the effusion of an
ideal gas between two compartments is calculated explicitly. The fluctuation
theorem is verified. The analytic results are in good agreement with numerical
data from hard disk molecular dynamics simulations.Comment: 11 pages, 10 figures, 2 table
Thermodynamic large fluctuations from uniformized dynamics
Large fluctuations have received considerable attention as they encode
information on the fine-scale dynamics. Large deviation relations known as
fluctuation theorems also capture crucial nonequilibrium thermodynamical
properties. Here we report that, using the technique of uniformization, the
thermodynamic large deviation functions of continuous-time Markov processes can
be obtained from Markov chains evolving in discrete time. This formulation
offers new theoretical and numerical approaches to explore large deviation
properties. In particular, the time evolution of autonomous and non-autonomous
processes can be expressed in terms of a single Poisson rate. In this way the
uniformization procedure leads to a simple and efficient way to simulate
stochastic trajectories that reproduce the exact fluxes statistics. We
illustrate the formalism for the current fluctuations in a stochastic pump
model
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
Dynamical fluctuations for semi-Markov processes
We develop an Onsager-Machlup-type theory for nonequilibrium semi-Markov
processes. Our main result is an exact large time asymptotics for the joint
probability of the occupation times and the currents in the system,
establishing some generic large deviation structures. We discuss in detail how
the nonequilibrium driving and the non-exponential waiting time distribution
influence the occupation-current statistics. The violation of the Markov
condition is reflected in the emergence of a new type of nonlocality in the
fluctuations. Explicit solutions are obtained for some examples of driven
random walks on the ring.Comment: Minor changes, accepted for publication in Journal of Physics
Al-B-C ternary compounds : synthesis, structure, composition and thermal stability
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