Résumé:

Pinning a fraction of particles in a liquid has been recently proposed as a means to probe high-order static and dynamics correlations. In particular, the response of model supercooled liquids to the external field exerted by a set of pinned particles has allowed to reveal growing point-to-set length scales [1] and the non-monotonic temperature dependence of a dynamic length scale [2]. To test the universality of these phenomena, we explore by numerical simulations the effect of different pinning geometries on various model liquids. We relate the observation of non-monotonic dynamic length scales in a weakly fragile, close-packed liquid to the suppression of static correlations reflecting the preferred local order of the liquid. The simulation results obtained by random pinning are discussed within the frameworks of the random first order transition theory and of the mode-coupling theory, and are compared to those obtained by studying finite size effects [3]. [1] G. M. Hocky, T. E. Markland, D. R. Reichman, Phys. Rev. Lett. 108, 225506 (2012) [2] W. Kob, S. Roldan-Vargas, L. Berthier, Nature Phys. 8, 697 (2012) [3] L. Berthier, G. Biroli, D. Coslovich, W. Kob, C. Toninelli, Phys. Rev. E 86, 031502 (2012)