Nature of crossover from classical to Ising-like critical behavior

TL;DR

This paper numerically investigates the transition from classical to Ising-like critical behavior in 3D systems, analyzing crossover scaling functions and challenging the validity of certain exponent relations.

Contribution

It provides detailed numerical analysis of the crossover region and tests the applicability of semi-phenomenological scaling functions in experimental data analysis.

Findings

Crossover behavior accurately characterized across the entire Ginzburg region

Semi-phenomenological scaling functions may not fully capture the crossover dynamics

Exponent relations between effective exponents do not hold in the studied regime

Abstract

We present an accurate numerical determination of the crossover from classical to Ising-like critical behavior upon approach of the critical point in three-dimensional systems. The possibility to vary the Ginzburg number in our simulations allows us to cover the entire crossover region. We employ these results to scrutinize several semi-phenomenological crossover scaling functions that are widely used for the analysis of experimental results. In addition we present strong evidence that the exponent relations do not hold between effective exponents.