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Title: Efficiency and large deviations in time-asymmetric stochastic heat engines

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. Lastly, we introduce a general approximation for the finite-time efficiency distribution, $$P(\eta )$$, based on large deviation statistics of work and heat, that remains very accurate even when $$P(\eta )$$ deviates significantly from its large deviation form.
 [1] ;  [2] ;  [3] ;  [4]
  1. Univ. of California, Berkeley, CA (United States). Dept. of Chemistry
  2. Univ. of California, Berkeley, CA (United States)
  3. Univ. of Chicago, IL (United States). James Franck Institute and Department of Chemistry
  4. Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division and Chemical Sciences Division
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
New Journal of Physics
Additional Journal Information:
Journal Volume: 16; Journal Issue: 10; Journal ID: ISSN 1367-2630
IOP Publishing
Research Org:
Univ. of California, Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Contributing Orgs:
Univ. of Chicago, IL (United States)
Country of Publication:
United States
42 ENGINEERING non-equilibrium fluctuations in small systems; molecular motors; large deviations in non-equilibrium systems