title: Structural signatures of dynamic heterogeneities in monolayers of colloidal ellipsoids.
abstract: When a liquid is supercooled towards the glass transition, its dynamics drastically slows down, whereas its static structure remains relatively unchanged. Finding a structural signature of the dynamic slowing down is a major challenge, yet it is often too subtle to be uncovered. Here we discover the structural signatures for both translational and rotational dynamics in monolayers of colloidal ellipsoids by video microscopy experiments and computer simulations. The correlation lengths of the dynamic slowest-moving clusters, the static glassy clusters, the static local structural entropy and the dynamic heterogeneity follow the same power-law divergence, suggesting that the kinetic slowing down is caused by a decrease in the structural entropy and an increase in the size of the glassy cluster. Ellipsoids with different aspect ratios exhibit single- or double-step glass transitions with distinct dynamic heterogeneities. These findings demonstrate that the particle shape anisotropy has important effects on the structure and dynamics of the glass.
authors.affiliation: 1] Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China [2] Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: Zhongyu
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: 1] Debye Institute for Nano Materials Science, Utrecht University, 3584 CC Utrecht, The Netherlands [2] Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands [3] Van't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: Ran
authors.initials: R
authors.lastname: Ni
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Debye Institute for Nano Materials Science, Utrecht University, 3584 CC Utrecht, The Netherlands.
authors.forename: Marjolein
authors.initials: M
authors.lastname: Dijkstra
authors.affiliation: Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Yuren
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: Yilong
authors.initials: Y
authors.lastname: Han