title: Flexible confinement leads to multiple relaxation regimes in glassy colloidal liquids.
abstract: Understanding relaxation of supercooled fluids is a major challenge and confining such systems can lead to bewildering behaviour. Here, we exploit an optically confined colloidal model system in which we use reduced pressure as a control parameter. The dynamics of the system are "Arrhenius" at low and moderate pressure, but at higher pressures relaxation is faster than expected. We associate this faster relaxation with a decrease in density adjacent to the confining boundary due to local ordering in the system enabled by the flexible wall.
authors.affiliation: H.H. Wills Physics Laboratory, Tyndall Ave., Bristol BS8 1TL, United Kingdom.
authors.forename: Ian
authors.initials: I
authors.lastname: Williams
authors.affiliation: Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Erdal C
authors.initials: EC
authors.lastname: Oğuz
authors.affiliation: School of Chemistry, Cantock's Close, University of Bristol, Bristol BS8 1TS, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Bartlett
authors.affiliation: Institut für Theoretische Physik II, Heinrich-Heine-Universität, D-40225 Düsseldorf, Germany.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Löwen
authors.affiliation: H.H. Wills Physics Laboratory, Tyndall Ave., Bristol BS8 1TL, United Kingdom.
authors.forename: C Patrick
authors.initials: CP
authors.lastname: Royall