Relevance of electron-lattice coupling in cuprates superconductors

TL;DR

This study demonstrates the significant role of electron-lattice coupling in cuprate superconductors by analyzing isotope and size effects, revealing how lattice distortions influence superconducting properties.

Contribution

It provides experimental evidence of the relevance of electron-lattice interactions involving oxygen lattice degrees of freedom in cuprate superconductors.

Findings

Isotope substitution affects superconducting domain size and penetration depth.

Electron-lattice coupling influences superfluid properties.

Oxygen lattice degrees of freedom are involved in superconductivity.

Abstract

We study the oxygen isotope (^{16}O,^{18}O) and finite size effects in Y_{1-x}Pr_{x}Ba_{2}Cu_{3}O_{7-\delta} by in-plane penetration depth (\lambda _{ab}) measurements. A significant change of the length L_{c} of the superconducting domains along the c-axis and \lambda_{ab}^{2} is deduced, yielding the relative isotope shift \Delta L_{c}/L_{c}\approx \Delta \lambda _{ab}^{2}/\lambda_{ab}^{2}\approx -0.14 for x=0, 0.2 and 0.3. This uncovers the existence and relevance of the coupling between the superfluid, lattice distortions and anharmonic phonons which involve the oxygen lattice degrees of freedom.