Detailed Fluctuation Theorems: A Unifying Perspective

in Entropy (2018), 20(9),

Kinetics and thermodynamics of a driven open quantum system

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2017), 96(5),

Carnot efficiency at divergent power output

in Europhysics Letters (2017), 118(40003),

The widely debated feasibility of thermodynamic machines achieving Carnot efficiency at finite power has been convincingly dismissed. Yet, the common wisdom that efficiency can only be optimal in the ... [more ▼]

The widely debated feasibility of thermodynamic machines achieving Carnot efficiency at finite power has been convincingly dismissed. Yet, the common wisdom that efficiency can only be optimal in the limit of infinitely slow processes overlooks the dual scenario of infinitely fast processes. We corroborate that efficient engines at divergent power output are not theoretically impossible, framing our claims within the theory of Stochastic Thermodynamics. We inspect the case of an electronic quantum dot coupled to three particle reservoirs to illustrate the physical rationale. [less ▲]

Quantum and Information Thermodynamics: A Unifying Framework Based on Repeated Interactions

in Physical Review X (2017), 7(021003),

We expand the standard thermodynamic framework of a system coupled to a thermal reservoir by <br />considering a stream of independently prepared units repeatedly put into contact with the system. These ... [more ▼]

We expand the standard thermodynamic framework of a system coupled to a thermal reservoir by <br />considering a stream of independently prepared units repeatedly put into contact with the system. These <br />units can be in any nonequilibrium state and interact with the system with an arbitrary strength and <br />duration. We show that this stream constitutes an effective resource of nonequilibrium free energy, and we <br />identify the conditions under which it behaves as a heat, work, or information reservoir. We also show that <br />this setup provides a natural framework to analyze information erasure (“Landauer’s principle”) and <br />feedback-controlled systems (“Maxwell’s demon”). In the limit of a short system-unit interaction time, we <br />further demonstrate that this setup can be used to provide a thermodynamically sound interpretation to <br />many effective master equations. We discuss how nonautonomously driven systems, micromasers, lasing <br />without inversion and the electronic Maxwell demon can be thermodynamically analyzed within our <br />framework. While the present framework accounts for quantum features (e.g., squeezing, entanglement, <br />coherence), we also show that quantum resources do not offer any advantage compared to classical ones in <br />terms of the maximum extractable work. [less ▲]

Kinetics and thermodynamics of a driven open quantum system

in Physical Review E (2017), 96(5),

Nonequilibrium Thermodynamics of Chemical Reaction Networks: Wisdom from Stochastic Thermodynamics

in Physical Review X (2016), 6(4), 041064

We build a rigorous nonequilibrium thermodynamic description for open chemical reaction networks of <br /><br />elementary reactions. Their dynamics is described by deterministic rate equations with mass ... [more ▼]

We build a rigorous nonequilibrium thermodynamic description for open chemical reaction networks of <br /><br />elementary reactions. Their dynamics is described by deterministic rate equations with mass action <br /><br />kinetics. Our most general framework considers open networks driven by time-dependent chemostats. <br /><br />The energy and entropy balances are established and a nonequilibrium Gibbs free energy is introduced. <br /><br />The difference between this latter and its equilibrium form represents the minimal work done by the <br /><br />chemostats to bring the network to its nonequilibrium state. It is minimized in nondriven detailed-balanced <br /><br />networks (i.e., networks that relax to equilibrium states) and has an interesting information-theoretic <br /><br />interpretation. We further show that the entropy production of complex-balanced networks (i.e., networks <br /><br />that relax to special kinds of nonequilibrium steady states) splits into two non-negative contributions: one <br /><br />characterizing the dissipation of the nonequilibrium steady state and the other the transients due to <br /><br />relaxation and driving. Our theory lays the path to study time-dependent energy and information <br /><br />transduction in biochemical networks. [less ▲]

Tightening the uncertainty principle for stochastic currents

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2016), 94(052104),

We connect two recent advances in the stochastic analysis of nonequilibrium systems: the (loose) uncertainty principle for the currents, which states that statistical errors are bounded by thermodynamic ... [more ▼]

We connect two recent advances in the stochastic analysis of nonequilibrium systems: the (loose) uncertainty principle for the currents, which states that statistical errors are bounded by thermodynamic dissipation, and the analysis of thermodynamic consistency of the currents in the light of symmetries. Employing the large deviation techniques presented by Gingrich et al. [Phys. Rev. Lett. 116, 120601 (2016)] and Pietzonka, Barato, and Seifert [Phys. Rev. E 93, 052145 (2016)], we provide a short proof of the loose uncertainty principle, and prove a tighter uncertainty relation for a class of thermodynamically consistent currents J . Our bound involves a measure of partial entropy production, that we interpret as the least amount of entropy that a system sustaining current J can possibly produce, at a given steady state. We provide a complete mathematical discussion of quadratic bounds which allows one to determine which are optimal, and finally we argue that the relationship for the Fano factor of the entropy production rate var σ/mean σ 2 is the most significant realization of the loose bound. We base our analysis both on the formalism of diffusions, and of Markov jump processes in the light of Schnakenberg’s cycle analysis. [less ▲]

Work producing reservoirs: Stochastic thermodynamics with generalized Gibbs ensembles

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2016), 94(020102),

We develop a consistent stochastic thermodynamics for environments composed of thermodynamic reservoirs in an external conservative force field, that is, environments described by the generalized or Gibbs ... [more ▼]

We develop a consistent stochastic thermodynamics for environments composed of thermodynamic reservoirs in an external conservative force field, that is, environments described by the generalized or Gibbs canonical ensemble. We demonstrate that small systems weakly coupled to such reservoirs exchange both heat and work by verifying a local detailed balance relation for the induced stochastic dynamics. Based on this analysis, we help to rationalize the observation that nonthermal reservoirs can increase the efficiency of thermodynamic heat engines. [less ▲]

Quantum Thermodynamics with Degenerate Eigenstate Coherences

in Entropy (2016), 18(447),

We establish quantum thermodynamics for open quantum systems weakly coupled to their reservoirs when the system exhibits degeneracies. The first and second law of thermodynamics are derived, as well as a ... [more ▼]

We establish quantum thermodynamics for open quantum systems weakly coupled to their reservoirs when the system exhibits degeneracies. The first and second law of thermodynamics are derived, as well as a finite-time fluctuation theorem for mechanical work and energy and matter currents. Using a double quantum dot junction model, local eigenbasis coherences are shown to play a crucial role on thermodynamics and on the electron counting statistics. [less ▲]

Glucans monomer-exchange dynamics as an open chemical network

in Journal of Chemical Physics (2015), 143

We describe the oligosaccharides-exchange dynamics performed by the so-called D-enzymes on polysaccharides. To mimic physiological conditions, we treat this process as an open chemical network by assuming ... [more ▼]

We describe the oligosaccharides-exchange dynamics performed by the so-called D-enzymes on polysaccharides. To mimic physiological conditions, we treat this process as an open chemical network by assuming some of the polymer concentrations fixed (chemostatting). We show that three different long-time behaviors may ensue: equilibrium states, nonequilibrium steady states, and continuous growth states. We dynamically and thermodynamically characterize these states and emphasize the crucial role of conservation laws in identifying the chemostatting conditions inducing them. [less ▲]