Field-mediated interactions of passive and conformation-active particles: multibody and retardation effects

Abstract

Particles in soft matter often interact through the deformation field they create, as in the "cheerios" effect or the curvature-mediated interactions of membrane proteins. Using a simple model for field-mediated...

Dynamics of a colloidal particle coupled to a Gaussian field: from a confinement-dependent to a non-linear memory

“…[30] together with the non-equilibrium relaxation of a particle which is released from an initial position away from the centre of the optical trap. Among the possible extensions of the present work, we mention considering a quadratic coupling of the particle to the field -which tends to move the probe towards the zeros of the field,more general couplings [19], or the case of anisotropic particles having a polarity coupled to gradients of the fluctuating field. Similarly, it would be interesting to explore additional and experimentally observable consequences of the emergence of the effective non-linear equation of motion of the particle beyond the dependence of the linear coefficients on the external forces.…”

“…In practice, the possibility to tune the correlation length ξ (and, correspondingly, the relaxation time of the relevant fluctuations) is offered by fluid solvents thermodynamically close to critical points, such as binary liquid mixtures, in which ξ diverges upon approaching the point of their phase diagrams corresponding to the demixing transition [12]. This model and variations thereof have been used in the literature in order to investigate theoretically the dynamics of freely diffusing or dragged particles [13,15,16], in the bulk or under spatial confinement [14] as well as the field-mediated interactions among particles and their phase behavior [17][18][19]. Here, instead, we use it in order to rationalise in a simple and natural setting the possible emergence of the issues mentioned above in interpreting microrheology data in the presence of correlated media.…”