TY - JOUR

T1 - Efficiency and large deviations in time-asymmetric stochastic heat engines

AU - Gingrich, Todd

AU - Rotskoff, Grant M.

AU - Vaikuntanathan, Suriyanarayanan

AU - Geissler, Phillip L.

N1 - Publisher Copyright:
© 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

PY - 2014/10/24

Y1 - 2014/10/24

N2 - In a stochastic heat engine driven by a cyclic non-equilibrium protocol, fluctuations in work and heat give rise to a fluctuating efficiency. Using computer simulations and tools from large deviation theory, we have examined these fluctuations in detail for a model two-state engine. We find in general that the form of efficiency probability distributions is similar to those described by Verley et al (2014 Nat. Commun. 5 4721), in particular featuring a local minimum in the long-time limit. In contrast to the time-symmetric engine protocols studied previously, however, this minimum need not occur at the value characteristic of a reversible Carnot engine. Furthermore, while the local minimum may reside at the global minimum of a large deviation rate function, it does not generally correspond to the least likely efficiency measured over finite time. We introduce a general approximation for the finite-time efficiency distribution, , based on large deviation statistics of work and heat, that remains very accurate even when deviates significantly from its large deviation form.

AB - In a stochastic heat engine driven by a cyclic non-equilibrium protocol, fluctuations in work and heat give rise to a fluctuating efficiency. Using computer simulations and tools from large deviation theory, we have examined these fluctuations in detail for a model two-state engine. We find in general that the form of efficiency probability distributions is similar to those described by Verley et al (2014 Nat. Commun. 5 4721), in particular featuring a local minimum in the long-time limit. In contrast to the time-symmetric engine protocols studied previously, however, this minimum need not occur at the value characteristic of a reversible Carnot engine. Furthermore, while the local minimum may reside at the global minimum of a large deviation rate function, it does not generally correspond to the least likely efficiency measured over finite time. We introduce a general approximation for the finite-time efficiency distribution, , based on large deviation statistics of work and heat, that remains very accurate even when deviates significantly from its large deviation form.

KW - Large deviations in non-equilibrium systems

KW - Molecular motors

KW - Non-equilibrium fluctuations in small systems

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U2 - 10.1088/1367-2630/16/10/102003

DO - 10.1088/1367-2630/16/10/102003

M3 - Article

AN - SCOPUS:84910131583

SN - 1367-2630

VL - 16

JO - New Journal of Physics

JF - New Journal of Physics

M1 - 102003

ER -