Kosterlitz-Thouless vs Ginzburg-Landau description of 2D superconducting fluctuations

TL;DR

This paper compares the Kosterlitz-Thouless and Ginzburg-Landau descriptions of 2D superconducting fluctuations by analyzing susceptibilities in the attractive Hubbard model and exploring topological fluctuation inclusion.

Contribution

It introduces a method to incorporate Kosterlitz-Thouless fluctuations into a perturbative framework using a modified correlation length.

Findings

Good agreement with Monte Carlo simulations

Demonstrates the feasibility of including topological fluctuations

Provides a new approach to modeling 2D superconducting fluctuations

Abstract

We evaluate the charge and spin susceptibilities of the 2D attractive Hubbard model and we compare our results with Montecarlo simulations on the same model. We discuss the possibility to include topological Kosterlitz-Thouless superconducting fluctuations in a standard perturbative approach substituting in the fluctuation propagator the Ginzburg-Landau correlation length with the Kosterlitz-Thouless correlation length.