The effect of GaP quantum dot luminescent addition on the superconducting properties and electron-phonon coupling in MgB₂

In this work, we investigate the impact of GaP quantum dot electroluminescent particles on the critical temperature (T_c), critical current density (J_c), flux pinning characteristics, and electron-phonon coupling (EPC) of MgB₂. A series of MgB₂ samples with varying electroluminescent intensities of GaP quantum dots were prepared using the solid-state sintering method, and the effect of inhomogeneous phase electroluminescence on the transition temperature improvement was studied. Raman spectroscopy was used to further reveal the changes in electron-phonon coupling (EPC), assessing the variation in the electron-phonon coupling coefficient driven by the photonic field energy. Furthermore, as an additive, GaP quantum dot electroluminescent particles introduced additional scattering centers and altered the microstructure, thereby improving the flux pinning effect, particularly enhancing the critical current density in high magnetic fields. The results show that the critical transition temperature of MgB₂ was increased by 0.8 K after the addition of the electroluminescent inhomogeneous phase, and the critical current density was significantly enhanced, especially under a 2 T external magnetic field, where it increased by 43.1 % compared to the undoped sample. These findings suggest that adding electroluminescent inhomogeneous phases is an effective strategy to enhance the superconducting performance of the material.