Persistent anti-correlations in Brownian dynamics simulations of dense colloidal suspensions revealed by noise suppression

Abstract

Transport properties of a hard-sphere colloidal fluid are investigated by Brownian dynamics simulations. We implement a novel algorithm for the time-dependent velocity-autocorrelation function (VACF) essentially eliminating the noise of the bare random motion. The measured VACF reveals persistent anti-correlations manifested by a negative algebraic power-law tail $t^{-5/2}$ at all densities. At small packing fractions, the simulations fully agree with the analytic low-density prediction, yet the amplitude of the tail becomes dramatically suppressed as the packing fraction is increased. The mode-coupling theory of the glass transition provides a qualitative explanation for the strong variation in terms of the static compressibility as well as the slowing down of the structural relaxation.

12 pages, 9 figures

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Cited by in corpus (5)

• Inertial effects of self-propelled particles: from active Brownian to active Langevin motion
• Emergence of molecular friction in liquids: bridging between the atomistic and hydrodynamic pictures
• Scaling equations for mode-coupling theories with multiple decay channels
• Tagged-particle dynamics in confined colloidal liquids
• Tagged-particle motion in quasi-confined colloidal hard-sphere liquids