Recent model simulations discovered unexpected nonmonotonic features in the wear-free dry phononic friction as a function of the sliding speed. Here we demonstrate that a rather straightforward application of linear-response theory, appropriate in a regime of weak slider-substrate interaction, predicts frictional one-phonon singularities which imply a nontrivial dependence of the dynamical friction force on the slider speed and/or coupling to the substrate. The explicit formula which we derive reproduces very accurately the classical atomistic simulations when available. By modifying the slider-substrate interaction the analytical understanding obtained provides a practical means to tailor and control the speed dependence of friction with substantial freedom.
Analytic understanding and control of dynamical friction
Tosatti E;
2018
Abstract
Recent model simulations discovered unexpected nonmonotonic features in the wear-free dry phononic friction as a function of the sliding speed. Here we demonstrate that a rather straightforward application of linear-response theory, appropriate in a regime of weak slider-substrate interaction, predicts frictional one-phonon singularities which imply a nontrivial dependence of the dynamical friction force on the slider speed and/or coupling to the substrate. The explicit formula which we derive reproduces very accurately the classical atomistic simulations when available. By modifying the slider-substrate interaction the analytical understanding obtained provides a practical means to tailor and control the speed dependence of friction with substantial freedom.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
