SearcharxivSearch

arXiv · cond-mat/9505014

A Testbench for the Nested Dipole Hypothesis of Kosterlitz and Thouless

Abstract

We consider the two-dimensional one-component plasma without a background and confined to a half plane near a metal wall. The particles are also subjected to an external potential acting perpendicular to the wall with an inverse power law Boltzmann factor. The model has a known solvable isotherm which exhibits a Kosterlitz-Thouless type transition from a conductive to an insulator phase as the power law is varied. This allows predictions of theoretical methods of analysing the Kosterlitz-Thouless transition to be compared with the exact solution. In particular we calculate the asymptotic density profile by resumming its low fugacity expansion near the zero-density critical coupling in the insulator phase, and solving a mean-field equation deduced from the first BGY equation. Agreement with the exact solution is obtained. As the former calculation makes essential use of the nested dipole hypothesis of Kosterlitz and Thouless, the validity of this hypothesis is explicitly verified.

Explore related subjects

Keep this discovery

BibTeXRIS

A. Alastuey, P. J. Forrester. 1995-05-03. A Testbench for the Nested Dipole Hypothesis of Kosterlitz and Thouless. https://doi.org/10.1007/bf02184869

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Towards quantum well hot hole lasers

It should be possible to improve hot-hole laser performance by moving from bulk materials to a quantum well structure. The extra design parameters enable us to alter the band structure by changing the crystal orientation of the growth direction; to use the well width to shift the subband offsets, enabling the effect of the LO phonon scattering cut-off to be controlled; and to use modulation doping to ensure a high hole concentration to increase the gain without the dopants being present in the gain region. We present the first simulations of THz quantum well hot-hole lasers that can produce inversion and optical gain.

cond-mat

Elastic response of [111]-tunneling impurities

We study the dynamic response of a [111] quantum impurity, such as lithium or cyanide in alkali halides, with respect to an external field coupling to the elastic quadrupole moment. Because of the particular level structure of a eight-state system on a cubic site, the elastic response function shows a biexponential relaxation feature and a van Vleck type contribution with a resonance frequency that is twice the tunnel frequency $Δ/\hbar$. This basically differs from the dielectric response that does not show relaxation. Moreover, we show that the elastic response of a [111] impurity cannot be reduced to that of a two-level system. In the experimental part, we report on recent sound velocity and internal friction measurements on KCl doped with cyanide at various concentrations. At low doping (45 ppm) we find the dynamics of a single [111] impurity, whereas at higher concentrations (4700 ppm) the elastic response rather indicates strongly correlated defects. Our theoretical model provides a good description of the temperature dependence of $δv/v$ and $Q^{-1}$ at low doping, in particular the relaxation peaks, the absolute values of the amplitude, and the resonant contributions. From our fits we obtain the value of the elastic deformation potential $γ_t=0.192$ eV.

cond-mat