Far-infrared measurements of oxygen-doped polycrystalline La2CuO4.0315 superconductor under slow-cooled and fast-cooled conditions

TL;DR

This study investigates the far-infrared charge dynamics of oxygen-doped La2CuO4+0.0315 under different cooling conditions, revealing two intrinsic superconducting transition temperatures linked to distinct electronic phase topologies.

Contribution

It provides new insights into how cooling rates affect superconducting properties and electronic phases in oxygen-doped La2CuO4+0.0315.

Findings

Superconducting transition temperatures are close to 30 K and 15 K for slow and fast cooling.

Electronic phases are associated with holes arranged in 2D square lattices.

Cooling conditions influence the topology of the electronic phases.

Abstract

We have studied the far-infrared (far-IR) charge dynamics of an equilibrated pure oxygen doped La2CuO4+0.0315 under slow-cooled and fast-cooled conditions. The superconducting transition temperature (Tc) for the slow-cooled and that for the fast-cooled processes were respectively found to be close to the two intrinsic Tc's: One at 30 K and the other at 15 K. Direct comparison with our previous results and other far-IR and Raman studies on single crystalline La2-xSrxCuO4, we conclude that the topology of the pristine electronic phases that are responsible for the two intrinsic Tc's is holes arranged into two-dimensional (2D) square lattices.