Comment to the paper : Collapse of the vortex-lattice inductance and shear modulus at the melting transition in untwinned YBa$_2$Cu$_3$O$_7$, by Matl \QTR{em}{et al.}

TL;DR

This paper critiques a recent high-frequency study of vortex lattice properties in YBaCuO, emphasizing the need for a more robust interpretation of complex resistivity data using the two modes model.

Contribution

It challenges the original analysis by Matl et al., proposing that their conclusions are based on fragile experimental interpretations and advocating for the two modes model as a more suitable framework.

Findings

Questions the validity of the original data analysis.

Suggests the two modes model as an alternative interpretation.

Highlights the importance of robust experimental and analytical methods.

Abstract

In a recent paper, Matl et al present a high-frequency study of the complex resistivity of a pinned vortex lattice in YBaCuO . They focus on the inductive-to-resistive transition which is investigated as a function of temperature at a constant field $B_0=2$ T, so that the transition is associated with the vanishing of vortex pinning strength. To our view, their conclusions rely on a rather brittle experimental body and the collapse of C66 results from an involved analysis of the finite frequency corrections to $\rho (\omega)$. These corrections are not necessary since the complex frequency spectrum has been previously interpreted by the two modes model, first proposed for low Tc materials. We think that it is more adequate to interpret the present data and should be at least considered.