Brownian duet: A novel tale of thermodynamic efficiency
  We calculate analytically the stochastic thermodynamic properties of an isothermal Brownian engine driven by a duo of time-periodic forces, including its Onsager coefficients, the stochastic work of each force, and the corresponding stochastic entropy production. We verify the relations between different operational regimes, maximum power, maximum efficiency and minimum dissipation, and reproduce the signature features of the stochastic efficiency. All these results are experimentally tested without adjustable parameters on a colloidal system. 
Karel Proesmans, Yannik Dreher, Mom\v{c}ilo Gavrilov, John Bechhoefer,   Christian Van den Broeck
cond-mat.stat-mech cond-mat.mes-hall