Energy versus information based estimations of dissipation using a pair of magnetic colloidal particles

• Published in: Physical review letters Vol. 112; no. 18; p. 180604
• Main Authors: Tusch, S, Kundu, A, Verley, G, Blondel, T, Miralles, V, Démoulin, D, Lacoste, D, Baudry, J
• Format: Journal Article
• Language: English
• Published: United States American Physical Society 09-05-2014
• Subjects: Classical Physics; Colloids; Complex systems; Computational fluid dynamics; Condensed Matter; Dissipation; Energy use; Fluid flow; Friction; Hydrodynamics; Physics; Soft Condensed Matter; Statistical Mechanics
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.112.180604

Using the framework of stochastic thermodynamics, we present an experimental study of a doublet of magnetic colloidal particles that is manipulated by a time-dependent magnetic field. Because of hydrodynamic interactions, each bead experiences a state-dependent friction, which we characterize using a hydrodynamic model. In this work, we compare two estimates of the dissipation in this system: the first one is energy based since it relies on the measured interaction potential, while the second one is information based since it uses only the information content of the trajectories. While the latter only offers a lower bound of the former, we find it to be simple to implement and of general applicability to more complex systems.