Current fluctuations and transport efficiency for general Langevin systems

Andreas Dechant, Shin Ichi Sasa

Research output: Contribution to journalArticlepeer-review

84 Citations (Scopus)


We derive a universal bound on generalized currents in Langevin systems in terms of the mean-square fluctuations of the current and the total entropy production. This bound generalizes a relation previously found by Barato et al to arbitrary times and transient states. Using the bound, we define a new efficiency for stochastic transport, which measures how close a given system comes to saturating the bound. The existence of such a bounded efficiency implies that stochastic transport is unavoidably accompanied by a fluctuations and dissipation, which cannot be reduced arbitrarily. We apply the definition of transport efficiency to steady state particle transport and heat engines and show that the transport efficiency may approach unity at finite current, in contrast to the thermodynamic efficiency. Finally, we derive a bound on purely diffusive transport in terms of the Shannon entropy.

Original languageEnglish
Article number063209
JournalJournal of Statistical Mechanics: Theory and Experiment
Issue number6
Publication statusPublished - 2018 Jun 25


  • diffusion
  • fluctuation phenomena
  • stochastic processes
  • transport processes/heat transfer

ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Statistics, Probability and Uncertainty


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