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DY: Fachverband Dynamik und Statistische Physik

DY 27: Statistical Physics far from Thermal Equilibrium II

DY 27.4: Vortrag

Dienstag, 10. März 2026, 14:45–15:00, ZEU/0114

Brownian gyrators: from mono- to quadrupolar gyration — •Iman Abdoli and Hartmut Löwen — Institut für Theoretische Physik II - Soft Matter, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany

Thermally anisotropic Brownian systems-where different spatial directions are coupled to different effective temperatures-break detailed balance and generate circulating probability currents, exemplified by the Brownian gyrator. Such systems provide a minimal framework for studying nonequilibrium energy conversion and the emergence of directed motion and torques driven purely by fluctuations. We demonstrate how these anisotropic fluctuations can be harnessed as a microscopic heat engine, whose efficiency can approach Carnot performance at maximum power when appropriately loaded with external mechanical forces [1]. Furthermore, we show that confining a thermally anisotropic particle to a narrow ring produces quadrupolar steady-state gyration, a symmetry-protected circulation pattern arising solely from anisotropic noise [2]. These results highlight the rich flux structures and energetic functionalities enabled by thermal anisotropy.

[1] I Abdoli, A Sharma, H Löwen, Phys. Fluids. 37 (4)

[2] I Abdoli, H Löwen, arXiv preprint arXiv:2508.08792

Keywords: Brownian gyrator; Quadrupolar gyration; Heat engine; Efficiency