Melting and Dimensionality of the Vortex Lattice in Underdoped YBa2Cu3O6.60

TL;DR

This study investigates the vortex lattice behavior in underdoped YBa2Cu3O6.60 superconductor, revealing a lower-temperature vortex melting transition and a decoupling of pancake vortices, with evidence of a dimensional crossover influenced by pinning effects.

Contribution

It provides new insights into vortex lattice melting and dimensional crossover in underdoped high-Tc superconductor YBa2Cu3O6.60, highlighting the role of layer decoupling and pinning.

Findings

Vortex lattice melts at lower temperature than in fully oxygenated YBa2Cu3O7.

Evidence of decoupling of pancake vortices in the liquid phase.

Pinning induces a crossover from 3D solid to quasi-2D vortex lattice.

Abstract

Muon spin rotation measurements of the magnetic field distribution in the vortex state of the oxygen deficient high-Tc superconductor YBa{2}Cu{3}O{6.60} reveal a vortex-lattice melting transition at much lower temperature than that in the fully oxygenated material. The transition is best described by a model in which adjacent layers of ``pancake'' vortices decouple in the liquid phase. Evidence is also found for a pinning-induced crossover from a solid 3D to quasi-2D vortex lattice, similar to that observed in the highly anisotropic superconductor Bi{2+x}Sr{2-x}CaCu{2}O{8+y}.