Brownian systems perturbed by mild shear: comparing response relations. (30th July 2021)

• Record Type: Journal Article
• Authors: Asheichyk, Kiryl; Fuchs, Matthias; Krüger, Matthias
• Is Part Of: Journal of physics. Volume 33:Number 40(2021)
• Publication Date: 2021-07-30
• Subjects: Brownian motion -- shear flow -- linear response theory in statistical physics -- fluctuation–dissipation theorem -- Green–Kubo relations; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/ac0c3c
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: We present a comprehensive study of the linear response of interacting underdamped Brownian particles to simple shear flow. We collect six different routes for computing the response, two of which are based on the symmetry of the considered system and observable with respect to the shear axes. We include the extension of the Green–Kubo relation to underdamped cases, which shows two unexpected additional terms. These six computational methods are applied to investigate the relaxation of the response towards the steady state for different observables, where interesting effects due to interactions and a finite particle mass are observed. Moreover, we compare the different response relations in terms of their statistical efficiency, identifying their relative demand on experimental measurement time or computational resources in computer simulations. Finally, several measures of breakdown of linear response theory for larger shear rates are discussed.