Evidence for magnetic-field-induced decoupling of superconducting bilayers in La$_{2-x}$Ca$_{1+x}$Cu$_{2}$O$_{6}$

TL;DR

This study investigates how an external magnetic field affects superconducting bilayers in La$_{2-x}$Ca$_{1+x}$Cu$_{2}$O$_{6}$, revealing magnetic-field-induced decoupling of layers through anisotropic resistivity and susceptibility measurements.

Contribution

It provides experimental evidence for magnetic-field-induced decoupling of superconducting bilayers in La$_{2-x}$Ca$_{1+x}$Cu$_{2}$O$_{6}$, highlighting anisotropic effects on superconductivity.

Findings

Resistive transition is lower when current is perpendicular to bilayers under magnetic field.

Anisotropic behavior observed in magnetic irreversibility points.

Evidence supports magnetic-field-induced decoupling of superconducting layers.

Abstract

We report a study of magnetic susceptibility and electrical resistivity as a function of temperature and magnetic field in superconducting crystals of La$_{2-x}$Ca$_{1+x}$Cu$_{2}$O$_{6}$ with $x=0.10$ and 0.15 and transition temperature $T_{c}^{\rm m} = 54$ K (determined from the susceptibility). When an external magnetic field is applied perpendicular to the CuO$_2$ bilayers, the resistive superconducting transition measured with currents flowing perpendicular to the bilayers is substantially lower than that found with currents flowing parallel to the bilayers. Intriguingly, this anisotropic behavior is quite similar to that observed for the magnetic irreversibility points with the field applied either perpendicular or parallel to the bilayers. We discuss the results in the context of other studies that have found evidence for the decoupling of superconducting layers induced by a perpendicular magnetic field.