title: Adiabatic processes realized with a trapped Brownian particle.
abstract: The ability to implement adiabatic processes in the mesoscale is of key importance in the study of artificial or biological micro- and nanoengines. Microadiabatic processes have been elusive to experimental implementation due to the difficulty in isolating Brownian particles from their fluctuating environment. Here we report on the experimental realization of a microscopic quasistatic adiabatic process employing a trapped Brownian particle. We circumvent the complete isolation of the Brownian particle by designing a protocol where both characteristic volume and temperature of the system are changed in such a way that the entropy of the system is conserved along the process. We compare the protocols that follow from either the overdamped or underdamped descriptions, demonstrating that the latter is mandatory in order to obtain a vanishing average heat flux to the particle. We provide analytical expressions for the distributions of the fluctuating heat and entropy and verify them experimentally. Our protocols could serve to implement the first microscopic engine that is able to attain the fundamental limit for the efficiency set by Carnot.
authors: ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.|Laboratoire de Physique, École Normale Supérieure, CNRS UMR5672 46 Allée d'Italie, 69364 Lyon, France.
authors: Ignacio A
authors: IA
authors: Martínez
authors: ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.|Max Planck Institute for the Physics of Complex Systems, Nöthnitzerstrasse 38, 01187 Dresden, Germany.|GISC-Grupo Interdisciplinar de Sistemas Complejos, Madrid, Spain.
authors: Édgar
authors: É
authors: Roldán
authors: GISC-Grupo Interdisciplinar de Sistemas Complejos, Madrid, Spain.|Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, 28040 Madrid, Spain.
authors: Luis
authors: L
authors: Dinis
authors: ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.|ICREA-Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain.
authors: Dmitri
authors: D
authors: Petrov
authors: ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.
authors: Raúl A
authors: RA
authors: Rica