Abstract

Zoom link: https://maths-cam-ac-uk.zoom.us/j/94018037756

Thermodynamic cycles with active matter: Active Brownian Particles (ABPs) can be used as a working fluid for a cyclically driven heat engine. This leads to protocols with features that can not be mimicked by equilibrium systems. Such protocols are “boundary driven”, in the sense that work can be extracted by only tweaking the details of the confining trap, even at a single reservoir temperature. We will discuss a procedure for optimising these protocols, as well as present a generic relation bounding the fluctuations in the output power. [1]

Power fluctuations in elastoplastic models: Elastoplastic models (EPMs) are simple theoretical constructions used to capture key aspects of a material’s response under loading. Despite their simplicity, they have been used to capture an array of real-world phenomenology, such as shear-banding and the yielding transition. A simulation study by Rabhari et al [2] investigated the fluctuations in the “local power injection” for a sheared system, and found that the character of rare fluctuations in this quantity changed dramatically across the jamming transition. In this talk, we show that a similar crossover in fluctuation behaviour can be seen within a variant of the foundational Hebraud-Lequex model.

[1] Phys. Rev. E 102, 010101R (2020), https://journals.aps.org/pre/abstract/10.1103/PhysRevE.102.010101

[2] Nat. Commun. 8, 11 (2017), https://www.nature.com/articles/s41467-017-00022-8