Properties of size-dependent models having quasiperiodic boundary conditions

Abstract

Boundary condition effects are explored for size-dependent models in thermal equilibrium. Scalar and fermionic models are used for [Formula: see text] (films), [Formula: see text] (hollow cylinder) and [Formula: see text] (ring). For all models, a minimal length is found, below which no thermally-induced phase transition occurs. Using quasiperiodic boundary condition controlled by a contour parameter [Formula: see text] ([Formula: see text] is a periodic boundary condition and [Formula: see text] is an antiperiodic condition), it results that the minimal length depends directly on the value of [Formula: see text]. It is also argued that this parameter can be associated to an Aharonov–Bohm phase.