Multiple singularities of the equilibrium free energy in a one-dimensional model of soft rods

Autor: Tridib Sadhu, Sushant Saryal, Deepak Dhar, Juliane U. Klamser
Rok vydání: 2018
Předmět:
DOI: 10.48550/arxiv.1806.09841
Popis: There is a misconception, widely shared amongst physicists, that the equilibrium free energy of a one-dimensional classical model with strictly finite-ranged interactions, and at non-zero temperatures, can not show any singularities as a function of the coupling constants. In this Letter, we discuss an instructive counter-example. We consider thin rigid linear rods of equal length $2 \ell$ whose centers lie on a one-dimensional lattice, of lattice spacing $a$. The interaction between rods is a soft-core interaction, having a finite energy $U$ per overlap of rods. We show that the equilibrium free energy per rod $\mathcal{F}(\tfrac{\ell}{a}, \beta)$, at inverse temperature $\beta$, has an infinite number of singularities, as a function of $\tfrac{\ell}{a}$.
Comment: 5 pages with additional 4 pages of supplemental material
Databáze: OpenAIRE