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Work statistics in stochastically driven systems Verley, Gatien ; ; Esposito, Massimiliano in New Journal of Physics (2014), 16 We identify the conditions under which a stochastic driving that induces energy changes into a system coupled with a thermal bath can be treated as a work source. When these conditions are met, the work ... [more ▼] We identify the conditions under which a stochastic driving that induces energy changes into a system coupled with a thermal bath can be treated as a work source. When these conditions are met, the work statistics satisfy the Crooks fluctuation theorem traditionally derived for deterministic drivings. We illustrate this fact by calculating and comparing the work statistics for a two-level system driven respectively by a stochastic and a deterministic piecewise constant protocol. [less ▲] Detailed reference viewed: 137 (9 UL)The unlikely Carnot efficiency Verley, Gatien ; Esposito, Massimiliano ; et al in Nature Communications (2014) The efficiency of an heat engine is traditionally defined as the ratio of its average output work over its average input heat. Its highest possible value was discovered by Carnot in 1824 and is a ... [more ▼] The efficiency of an heat engine is traditionally defined as the ratio of its average output work over its average input heat. Its highest possible value was discovered by Carnot in 1824 and is a cornerstone concept in thermodynamics. It led to the discovery of the second law and to the definition of the Kelvin temperature scale. Small-scale engines operate in the presence of highly fluctuating input and output energy fluxes. They are therefore much better characterized by fluctuating efficiencies. In this study, using the fluctuation theorem, we identify universal features of efficiency fluctuations. While the standard thermodynamic efficiency is, as expected, the most likely value, we find that the Carnot efficiency is, surprisingly, the least likely in the long time limit. Furthermore, the probability distribution for the efficiency assumes a universal scaling form when operating close-to-equilibrium. We illustrate our results analytically and numerically on two model systems. [less ▲] Detailed reference viewed: 362 (125 UL)Stochastically driven single-level quantum dot: A nanoscale finite-time thermodynamic machine and its various operational modes Esposito, Massimiliano ; ; et al in Physical Review E (2012), 85(3), We describe a single-level quantum dot in contact with two leads as a nanoscale finite-time thermodynamic machine. The dot is driven by an external stochastic force that switches its energy between two ... [more ▼] We describe a single-level quantum dot in contact with two leads as a nanoscale finite-time thermodynamic machine. The dot is driven by an external stochastic force that switches its energy between two values. In the isothermal regime, it can operate as a rechargeable battery by generating an electric current against the applied bias in response to the stochastic driving and then redelivering work in the reverse cycle. This behavior is reminiscent of the Parrondo paradox. If there is a thermal gradient the device can function as a work-generating thermal engine or as a refrigerator that extracts heat from the cold reservoir via the work input of the stochastic driving. The efficiency of the machine at maximum power output is investigated for each mode of operation, and universal features are identified. [less ▲] Detailed reference viewed: 89 (3 UL)Thermodynamics of a stochastic twin elevator ; ; Esposito, Massimiliano et al in Physical Review E (2011), 84(5), We study the nonequilibrium thermodynamics of a single particle with two available energy levels, in contact with a classical (Maxwell-Boltzmann) or quantum (Bose-Einstein) heat bath. The particle can ... [more ▼] We study the nonequilibrium thermodynamics of a single particle with two available energy levels, in contact with a classical (Maxwell-Boltzmann) or quantum (Bose-Einstein) heat bath. The particle can undergo transitions between the levels via thermal activation or deactivation. The energy levels are alternately raised at a given rate regardless of occupation by the particle, maintaining a fixed energy gap equal to ε between them. We explicitly calculate the work, heat, and entropy production rates. The efficiency in both the classical and the quantum case goes to a limit between 100 and 50% that depends on the relative rates of particle transitions and level elevation. In the classical problem we explicitly find the large deviation functions for heat, work, and internal energy. [less ▲] Detailed reference viewed: 661 (0 UL)Three faces of the second law. I. Master equation formulation Esposito, Massimiliano ; in Physical Review E (2010), 82(1), We propose a formulation of stochastic thermodynamics for systems subjected to nonequilibrium constraints i.e. broken detailed balance at steady state and furthermore driven by external time-dependent ... [more ▼] We propose a formulation of stochastic thermodynamics for systems subjected to nonequilibrium constraints i.e. broken detailed balance at steady state and furthermore driven by external time-dependent forces. A splitting of the second law occurs in this description leading to three second-law-like relations. The general results are illustrated on specific solvable models. The present paper uses a master equation based approach. [less ▲] Detailed reference viewed: 65 (0 UL)Extracting chemical energy by growing disorder: efficiency at maximum power Esposito, Massimiliano ; ; in Journal of Statistical Mechanics : Theory and Experiment (2010) We consider the efficiency of chemical energy extraction from the environment by the growth of a copolymer made of two constituent units in the entropy-driven regime. We show that the thermodynamic ... [more ▼] We consider the efficiency of chemical energy extraction from the environment by the growth of a copolymer made of two constituent units in the entropy-driven regime. We show that the thermodynamic nonlinearity associated with the information processing aspect is responsible for a branching of the system properties such as power, speed of growth, entropy production, and efficiency, with varying affinity. The standard linear thermodynamics argument which predicts an efficiency of 1/2 at maximum power is inappropriate because the regime of maximum power is located either outside of the linear regime or on a separate bifurcated branch, and because the usual thermodynamic force is not the natural variable for this optimization. [less ▲] Detailed reference viewed: 48 (0 UL)Efficiency at Maximum Power of Low-Dissipation Carnot Engines Esposito, Massimiliano ; ; et al in Physical Review Letters (2010), 105(15), Detailed reference viewed: 62 (0 UL)Entropy production as correlation between system and reservoir Esposito, Massimiliano ; ; in New Journal of Physics (2010), 12 We derive an exact (classical and quantum) expression for the entropy production of a finite system placed in contact with one or several finite reservoirs, each of which is initially described by a ... [more ▼] We derive an exact (classical and quantum) expression for the entropy production of a finite system placed in contact with one or several finite reservoirs, each of which is initially described by a canonical equilibrium distribution. Although the total entropy of system plus reservoirs is conserved, we show that system entropy production is always positive and is a direct measure of system–reservoir correlations and/or entanglements. Using an exactly solvable quantum model, we illustrate our novel interpretation of the Second Law in a microscopically reversible finite-size setting, with strong coupling between the system and the reservoirs. With this model, we also explicitly show the approach of our exact formulation to the standard description of irreversibility in the limit of a large reservoir. [less ▲] Detailed reference viewed: 67 (0 UL)Three Detailed Fluctuation Theorems Esposito, Massimiliano ; in Physical Review Letters (2010), 104(9), The total entropy production of a trajectory can be split into an adiabatic and a nonadiabatic contribution, deriving, respectively, from the breaking of detailed balance via nonequilibrium boundary ... [more ▼] The total entropy production of a trajectory can be split into an adiabatic and a nonadiabatic contribution, deriving, respectively, from the breaking of detailed balance via nonequilibrium boundary conditions or by external driving.We show that each of them, the total, the adiabatic, and the nonadiabatic trajectory entropy, separately satisfies a detailed fluctuation theorem. [less ▲] Detailed reference viewed: 64 (0 UL)Three faces of the second law. II. Fokker-Planck formulation ; Esposito, Massimiliano in Physical Review E (2010), 82(1), The total entropy production is the sum of two contributions, the so-called adiabatic and nonadiabatic entropy productions, each of which is non-negative. We derive their explicit expressions for ... [more ▼] The total entropy production is the sum of two contributions, the so-called adiabatic and nonadiabatic entropy productions, each of which is non-negative. We derive their explicit expressions for continuous Markovian processes, discuss their properties, and illustrate their behavior on two exactly solvable models. [less ▲] Detailed reference viewed: 62 (0 UL)Quantum-dot Carnot engine at maximum power Esposito, Massimiliano ; ; et al in Physical Review E (2010), 81(4), We evaluate the efficiency at maximum power of a quantum-dot Carnot heat engine. The universal values of the coefficients at the linear and quadratic order in the temperature gradient are reproduced ... [more ▼] We evaluate the efficiency at maximum power of a quantum-dot Carnot heat engine. The universal values of the coefficients at the linear and quadratic order in the temperature gradient are reproduced. Curzon-Ahlborn efficiency is recovered in the limit of weak dissipation. [less ▲] Detailed reference viewed: 78 (0 UL)Universality of Efficiency at Maximum Power Esposito, Massimiliano ; ; in Physical Review Letters (2009), 102(13), Detailed reference viewed: 78 (2 UL) |
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