Crystal-lattice coupling to the vortex-melting transition in YBa2Cu3O7-d

TL;DR

This study reveals a strong coupling between the vortex-melting transition and the crystal lattice in YBa2Cu3O7-d, showing that lattice changes are directly linked to vortex behavior, driven by pressure-dependent superconducting properties.

Contribution

It provides direct experimental evidence of lattice discontinuities at the vortex melting transition, highlighting the lattice's active role in vortex physics in high-temperature superconductors.

Findings

Discontinuities in thermal expansion at vortex melting point

Coupling between vortex transition and lattice structure

Pressure dependence of superconducting transition temperature

Abstract

Distinct discontinuities in the thermal expansion of the crystal lattice are observed at the melting-transition of the vortex lattice in a naturally untwinned reversible YBa2Cu3O7-d-single crystal using high-resolution dilatometry. This coupling between the vortex transition and the crystal lattice demonstrates that the crystal lattice is more than a mere host for the vortices, and it is attributed to a strong pressure dependence of the superconducting transition temperature and thus to the condensation energy at the vortex melting temperature.