Berlin 2018 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 10: Statistical Physics I (General)
DY 10.4: Talk
Monday, March 12, 2018, 10:45–11:00, BH-N 333
A new perspective on laser-induced freezing and reentrant melting — •Alexander Kraft and Sabine H. L. Klapp — Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin
Laser-induced freezing (LIF) of a two-dimensional colloidal system describes the phenomenon in which a one-dimensional interfering laser beam pattern can induce a liquid-crystal freezing transition [1]. In this contribution, we propose a new perspective of the microscopic origin of LIF. Using free minimization techniques within density functional theory for a model system subjected to two different substrate potentials, we show that there is strong evidence that the increase of the light intensity is not the only reason for the occurrence of LIF, but its accompanying side-effect to increase the effective average density. In our approach, we characterize the inhomogeneous density distribution of particles in terms of two quantities: We introduce a confining length Lc to characterize the region within which a representative fraction of particles are confined and the effective average density ρeff within this region. In this way, our approach allows to make theoretical predictions for the critical value of the light intensity for the onset of LIF and allows to define a quantitative measure for the reduced registration introduced by [2] to understand reentrant melting.
- [1] A. Chowdhury et al., Phys. Rev. Lett. 55, 833 (1985)
- [2] Q. H. Wei et al., Phys. Rev. Lett. 81, 2606 (1998)
- [3] L. Radzihovsky et al. Phys. Rev. E 63, 031503 (2001)