Dresden 2017 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 36: Brownian Motion (jointly with DY)

TT 36.11: Talk

Tuesday, March 21, 2017, 12:45–13:00, ZEU 147

Brownian Carnot Engine — •Edgar Roldan¹, Ignacio A. Martinez^2,3, Luis Dinis³, Juan MR Parrondo³, Raul A. Rica^4,5, and Dmitry Petrov⁴ — ¹Max Planck Institut fur Physik Komplexer Systeme — ²Ecole Normale Superieure de Lyon — ³Universidad Complutense de Madrid and GISC — ⁴ICFO The Institute of Photonic Sciences — ⁵Universidad de Granada

The Carnot cycle imposes a fundamental upper limit to the efficiency of a macroscopic motor operating between two thermal baths. However, this bound needs to be reinterpreted at microscopic scales, where molecular motors and some artificial micro-engines, operate. Energy transfers in microscopic systems are random and thermal fluctuations induce transient decreases of entropy, allowing for possible violations of the Carnot limit. Nearly two centuries after Carnot's work, we report an experimental realization of a Carnot engine with a single optically trapped Brownian particle as the working substance. We present an exhaustive study of the energetics of the engine and analyse the fluctuations of the finite-time efficiency, showing that the Carnot bound can be surpassed for a small number of non-equilibrium cycles. As its macroscopic counterpart, the energetics of our Carnot machine exhibits basic properties that one would expect to observe in any microscopic energy transducer operating with baths at different temperatures. Our results characterize the sources of irreversibility in the engine and the statistical properties of the efficiency, an insight that could inspire new strategies in the design of efficient nano-motors.