Towards a two-dimensional superconducting state of La$_{2-x}$Sr$_{x}$CuO$_{2}$ in a moderate external magnetic field

TL;DR

This study reveals that applying a moderate magnetic field suppresses interlayer coupling in underdoped La214 cuprates, while preserving in-plane superconductivity, highlighting the complex interplay between magnetism and superconductivity.

Contribution

It demonstrates the complete suppression of interlayer coupling under a magnetic field in underdoped La214, a novel insight into the magnetic-superconducting competition.

Findings

Interlayer coupling is fully suppressed by a modest magnetic field.

In-plane superconductivity remains unaffected despite increased magnetism.

Magnetic field influences interlayer interactions without destroying superconductivity.

Abstract

We report a novel aspect of the competition and coexistence between magnetism and superconductivity in the high-$T_{c}$ cuprate La$_{2-x}$Sr$_{x}$CuO$_{4}$ (La214). With a modest magnetic field applied $H \parallel c$-axis, we monitored the infrared signature of pair tunneling between the CuO$_2$ planes and discovered the complete suppression of interlayer coupling in a series of underdoped La214 single crystals. We find that the in-plane superconducting properties remain intact, in spite of enhanced magnetism in the planes.