Critical Casimir Force between Inhomogeneous Boundaries

Jerome Dubail 1 Raoul Santachiara 2 Thorsten Emig 3, 2

EPL, European Physical Society/EDP Sciences/Società Italiana di Fisica/IOP Publishing, 2015, 112, pp.66004

To study the critical Casimir force between chemically structured boundaries immersed in a binary mixture at its demixing transition, we consider a strip of Ising spins subject to alternating fixed spin boundary conditions. The system exhibits a boundary induced phase transition as function of the relative amount of up and down boundary spins. This transition is associated with a sign change of the asymptotic force and a diverging correlation length that sets the scale for the crossover between different universal force amplitudes. Using conformal field theory and a mapping to Majorana fermions, we obtain the universal scaling function of this crossover, and the force at short distances.

  • 1. IJL - Institut Jean Lamour
  • 2. LPTMS - Laboratoire de Physique Théorique et Modèles Statistiques
  • 3. Massachussetts Institute of Technology