Abolfazl Ahmadirahmat & Michele Caraglio (Institut für Theoretische Physik, Universität Innsbruck, Austria), Vincent Krakoviack (ENS de Lyon, CNRS, Laboratoire de Chimie (LCH UMR5182) et Centre Blaise Pascal, 69342 Lyon cedex 07, France), Thomas Franosch (Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 25/2, A-6020 Innsbruck, Austria)
We present an extension of mode-coupling theory for dense colloidal suspensions in (d+1) dimensions subjected to a one-dimensional periodic external potential. Combining integral-equation theory and mode-coupling theory, we study (2D) hard disks under periodic modulation and determine the nonequilibrium glass-transition diagram as a function of packing fraction, field period, and potential strength.
The competition between local packing constraints and the commensurability of the imposed periodicity produces distinct particle-caging geometries and leads to a strongly non-monotonic dependence of the glass transition on the field period. As a result, tuning the external field can either melt an arrested state or induce strong vitrification at moderate densities. These effects arise from the incommensurability or commensurability between the local packing length scale and the external-field period. We identify regions where moderate modulation stabilizes the liquid state, while other field periods enhance glass formation. The corresponding nonergodicity parameters reveal how the external potential reshapes the microscopic cages responsible for dynamical arrest. Our results demonstrate that periodic external fields provide a powerful route to controlling the liquid–glass transition, an effect we refer to as light-induced caging.