Presentation by A. Argun at OSA Life Sciences Conference, Tucson, 14-17 April 2019

Statistics of Brownian particles held in non-harmonic potentials in an active bath

Aykut Argun and Giovanni Volpe
OSA Life Sciences Conference,
Tucson, 14-17 April 2019


Active systems are subject to persistent noise that arise from biological media or artificial activity like self-propelled particles. Therefore, these systems are  intrinsically out of equilibrium and can only be studied within the framework of non-equilibrium physics. So far, steady-state behavior and dynamical fluctuations of Brownian particles in active baths have been investigated both theoretically and experimentally. While some of the equilibrium properties can be retained by using an effective temperature, for most systems this generalization is not possible. Here, we extend the existing studies to non-harmonic potential cases, where other qualitative distinctions of the active matter emerge.

Talk on optical tweezers by Aykut Argun at Gothenburg PhD Pub. 17 Oct 2018

Aykut Argun will present a popular science talk on the principles and applications of optical tweezers at a PhD-student event called Gothenburg Ph.D. Pub.

Title: Optical tweezers and applications

Abstract: Can objects be moved contact-free only by the power of light?
The answer which deserved a Nobel Prize in Physics last week is yes.
Aykut Argun from GU Physics will present how in the next Ph.D. Pub.

Place: Haket – Bar å sånt, Första långgatan 32, 413 27 Gothenburg
Time: Wednesday, October 17, 2018 at 7 PM – 10 PM

Talk by A. Argun at IONS Scandinavia 2018, Copenhagen, 5-9 Jun 2018

Experimental realization of a minimal microscopic heat engine
Aykut Argun, Jalpa Soni, Lennart Dabelow, Stefano Bo, Giuseppe Pesce,
Ralf Eichborn & Giovanni Volpe
IONS Scandinavia 2018, Copenhagen, Denmark
5-9 June 2018

Abstract:  Microscopic heat engines are microscale systems that convert energy flows between heat reservoirs into work or systematic motion. We have experimentally realized a minimal microscopic heat engine. It consists of a colloidal Brownian particle optically trapped in an elliptical potential well and simultaneously coupled to two heat baths at different temperatures acting along perpendicular directions. For a generic arrangement of the principal directions of the baths and the potential, the symmetry of the system is broken, such that the heat flow drives a systematic gyrating motion of the particle around the potential minimum. Using the experimentally measured trajectories, we quantify the gyrating motion of the particle, the resulting torque that it exerts on the potential, and the associated heat flow between the heat baths. We find excellent agreement between the experimental results and the theoretical predictions. 

Reference: Argun et al. Experimental realization of a minimal microscopic heat engine. Physical Review E 96(5), 052106 (2017)