2004/12/10 by K. Borkje, S. Kragset, A. Sudbo
Physics and Astronomy · #cond-mat.stat-mech #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.71.085112
published as Phys. Rev. B 71, 085112 (2005) · 15 pages, 16 figures
arxiv created 2004/12/10 · arxiv updated 2009/12/01
The existence of a discontinuity in the inverse dielectric constant of the two-dimensional Coulomb gas is demonstrated on purely numerical grounds. This is done by expanding the free energy in an applied twist and performing a finite-size scaling analysis of the coefficients of higher-order terms. The phase transition, driven by unbinding of dipoles, corresponds to the Kosterlitz-Thouless transition in the 2D XY model. The method developed is also used for investigating the possibility of a Kosterlitz-Thouless phase transition in a three-dimensional system of point charges interacting with a logarithmic pair-potential, a system related to effective theories of low-dimensional strongly correlated systems. We also contrast the finite-size scaling of the fluctuations of the dipole moments of the two-dimensional Coulomb gas and the three-dimensional logarithmic system to those of the three-dimensional Coulomb gas.