English

Critical Behavior in Rectangles with Mixed Boundaries

Statistical Mechanics 2023-07-18 v1

Abstract

Density profiles are investigated arising in a critical Ising model in two dimensions which is confined to a rectangular domain with uniform or mixed boundary conditions and arbitrary aspect ratio. For the cases in which the two vertical sides of the rectangle have up-spin boundary conditions + and the two horizontal sides with either down-spin boundary conditions - or with free-spin boundary conditions ff, exact results are presented for the density profiles of the energy and the order parameter which display a surprisingly rich behavior. The new results follow by means of conformal transformations from known results in the half plane with ++++-+-+ and +f+f++f+f+ boundary conditions. The corners with mixed boundary conditions lead to interesting behavior, even in the limit of a half-infinite strip. The behavior near these corners can be described by a ``Corner-Operator-Expansion'', which is discussed in the second part of the paper. The analytic predictions agree very well with simulations, with no adjustable parameters.

Keywords

Cite

@article{arxiv.2307.07831,
  title  = {Critical Behavior in Rectangles with Mixed Boundaries},
  author = {E. Eisenriegler},
  journal= {arXiv preprint arXiv:2307.07831},
  year   = {2023}
}
R2 v1 2026-06-28T11:31:21.175Z