Vortex Origin of Tricritical Point in Ginzburg-Landau Theory

TL;DR

This paper demonstrates that vortex fluctuations in Ginzburg-Landau theory can explain the tricritical point in high-temperature superconductors, clarifying discrepancies between theoretical predictions and experimental observations.

Contribution

It provides a novel derivation of the tricritical point from vortex fluctuations, addressing limitations of standard renormalization group approaches.

Findings

Vortex fluctuations lead to a tricritical point in Ginzburg-Landau theory.

Standard RG arguments predict a first-order transition, conflicting with experiments.

The derivation aligns theoretical predictions with experimental and simulation results.

Abstract

Motivated by recent experimental progress in the critical regime of high-$T_c$ superconductors we show how the tricritical point in a superconductor can be derived from the Ginzburg-Landau theory as a consequence of vortex fluctuations. Our derivation explains why usual renormalization group arguments always produce a first-order transition, in contrast to experimental evidence and Monte Carlo simulations.