Interacting hard rigid rotors on a d-dimensional lattice

Statistical Physics and Complexity Group meeting

Interacting hard rigid rotors on a d-dimensional lattice

  • Event time: 3:00pm until 4:00pm
  • Event date: 22nd November 2022
  • Speaker: Professor Deepak Dhar (Department of Physics, Indian Institute of Science Research and Education, Pune)
  • Location: Online - see email.

Event details

We consider a system of interacting identical molecules, where each molecule is an extended object, and has one point pivoted to a vertex of a regular lattice, and thus has no translational degree of freedom but can take arbitrary orientations, subject to the constraint that different molecules can not overlap. When the pivoting point is situated asymmetrically on the object, we show that there is a range of lattice spacings a, where in any orientation, a particle can overlap with at most one of its neighbours. In this range, the entropy of the system of particles can be expressed exactly in terms of the grand partition function of coverings of the base lattice by dimers at a finite negative activity. Calculation of the partition function is also shown to be reducible to that of the same model with discretized orientations. We determine the exact functional form of the probability distribution function of orientations at a site. This shows multiple cusp singularities as a function of the ratio of size of the molecules and the lattice spacing.

Event resources