Depinning and structural transitions in a 2D model of colloids
نویسندگان
چکیده
A recent experimental research carried out by Bohlein and collaborators shows how colloidal particle crystals trapped in laser interference fields can cast new light on elementary frictional processes in ideally controlled sliding systems. Driven colloidal friction provides an unprecedented realtime insight into the elementary microscopic dynamical mechanisms at play. In the present work we simulate numerically the motion of a monolayer of charged colloidal particles in interaction with a lattice-mismatched periodical potential, in the spirit of Bohlein’s experiment. We address two related features: (i) the competition of a variety of mechanically stable structural configurations arising as local minima of the total energy, as a function of the relative strength of the interparticle repulsion and the periodic potential; (ii) the depinning transition under the effect of an applied external force, suggestive of static friction measurements, and the effect of the competing configurations on the critical depinning force. Advisor: Prof. Nicola Manini Co-Advisor: Prof. Andrea Vanossi
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تاریخ انتشار 2013