Systematic behaviour of the in-plane penetration depth in d-wave cuprates

TL;DR

This study investigates how the in-plane and out-of-plane penetration depths in YBa_2Cu_3O_{7- extdelta} vary with temperature and oxygen content, revealing systematic changes linked to superconducting properties.

Contribution

It provides a systematic analysis of the penetration depth behavior in cuprates with different oxygen doping levels, highlighting how these parameters evolve with doping and temperature.

Findings

Penetration depths increase with oxygen deficiency.

Linear temperature term in mbda_{ab}(T) varies systematically with T_c.

Ratio mbda_{c}(0)/mbda_{ab}(T) changes with doping.

Abstract

We report the temperature T and oxygen concentration dependences of the penetration depth of grain-aligned YBa_2Cu_3O_{7-\delta} with \delta= 0.0, 0.3 and 0.43. The values of the in-plane \lambda_{ab}(0) and out-of-plane \lambda_{c}(0) penetration depths, the low temperature linear term in \lambda_{ab}(T), and the ratio \lambda_{c}(0) /\lambda_{ab}(T) were found to increase with increasing $\delta$. The systematic changes of the linear term in \lambda_{ab}(T) with T_c found here and in recent work on HgBa_2Ca_{n-1} Cu_nO_{2n+2+\delta} (n = 1 and 3) are discussed.