%0 Journal Article %T Crossovers in the dynamics of supercooled liquids probed by an amorphous wall %+ Columbia University [New York] %+ Laboratoire Charles Coulomb (L2C) %A Hocky, Glen M %A Berthier, Ludovic %A Kob, Walter %A Reichman, David R. %Z 9 pages, 7 figures %< avec comité de lecture %Z L2C:14-042 %@ 1539-3755 %J Physical Review E : Statistical, Nonlinear, and Soft Matter Physics %I American Physical Society %V 89 %P 052311 %8 2014-06-02 %D 2014 %Z 1402.5974 %R 10.1103/PhysRevE.89.052311 %Z Physics [physics]/Condensed Matter [cond-mat]/Statistical Mechanics [cond-mat.stat-mech] %Z Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]Journal articles %X We study the relaxation dynamics of a binary Lennard-Jones liquid in the presence of an amorphous wall generated from equilibrium particle configurations. In qualitative agreement with the results presented in Nature Phys. {\bf 8}, 164 (2012) for a liquid of harmonic spheres, we find that our binary mixture shows a saturation of the dynamical length scale close to the mode-coupling temperature $T_c$. Furthermore we show that, due to the broken symmetry imposed by the wall, signatures of an additional change in dynamics become apparent at a temperature well above $T_c$. We provide evidence that this modification in the relaxation dynamics occurs at a recently proposed dynamical crossover temperature $T_s > T_c$, which is related to the breakdown of the Stokes-Einstein relation. We find that this dynamical crossover at $T_s$ is also observed for a system of harmonic spheres as well as a WCA liquid, showing that it may be a general feature of glass-forming systems. %G English %2 https://hal.science/hal-00998409/document %2 https://hal.science/hal-00998409/file/PhysRe3.pdf %L hal-00998409 %U https://hal.science/hal-00998409 %~ CNRS %~ L2C %~ MIPS %~ UNIV-MONTPELLIER %~ UM-2015-2021