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DY: Fachverband Dynamik und Statistische Physik
DY 56: Brownian Motion and Anomalous Diffusion
DY 56.1: Talk
Friday, March 31, 2023, 09:30–09:45, ZEU 160
Odd Diffusion of Interacting Particles — •Erik Kalz1, Hidde Derk Vuijk2, Iman Abdoli2, Jens-Uwe Sommer2,3, Hartmut Löwen4, Ralf Metzler1, and Abhinav Sharma2,3 — 1Universität Potsdam, Institut für Physik und Astronomie — 2Leibniz-Institut für Polymerforschung Dresden, Institut Theorie der Polymere — 3Technische Universität Dresden, Institut für Theoretische Physik — 4Heinrich Heine-Universität Düsseldorf, Institut für Theoretische Physik II: Weiche Materie
It is generally believed that collisions of particles reduce the self-diffusion coefficient, closely related to autocorrelation functions, which are assumed to decay monotonously in the overdamped limit. We show that these beliefs are only limiting cases in odd-diffusive systems, which are characterized by diffusion tensors with antisymmetric offdiagonal elements. We show that in the dilute limit, particle interactions can reduce, unalter and even enhance the self-diffusion. The underlying particle dynamics thereby can be captured by the force autocorrelation function. We show that this autocorrelation function exhibits a variety of behaviour: (a) even in the dilute limit where collisions are rare, the correlation can become negative, (b) despite the overdamped dynamics, the force autocorrelation can exhibit temporal oscillations and (c) the long-time power-law decay of the force autocorrelation depends on the odd-diffusion parameter. Odd diffusivity, therefore, shines new light on fundamental beliefs in overdamped systems.
Kalz, Erik, et al. Collisions enhance self-diffusion in odd-diffusive systems. Physical Review Letters 129.9 (2022): 090601.