The interaction between the magnetic and superconducting order parameters in a La1.94Sr0.06CuO4 wire

TL;DR

This study explores how magnetic and superconducting properties interact in a La1.94Sr0.06CuO4 wire, revealing that suppressing superconductivity enhances magnetic transition temperature, indicating a repulsive coupling between the two orders.

Contribution

It provides experimental evidence of the coupling nature between magnetic and superconducting orders in a cuprate wire, highlighting the system's proximity to a phase transition boundary.

Findings

Suppression of superconductivity raises magnetic transition temperature.

Magnetic and superconducting orders exhibit a repulsive interaction.

System is near the boundary between first and second order phase transitions.

Abstract

We investigate the coupling between the magnetic and superconducting order parameters in an 8 m long meander line ("wire") made of a La1.94Sr0.06CuO4 film with a cross section of 0.5 x 100 um^2. The magnetic order parameter is determined using the Low-Energy muon spin relaxation technique. The superconducting order parameter is characterized by transport measurements and modified by high current density. We find that, when the superconducting order parameter is suppressed by the current, the magnetic transition temperature, Tm, increases. The extracted sign and magnitude of the Ginzburg-Landau coupling constant indicate that the two orders are repulsive, and that our system is located close to the border between first and second order phase transition.