The Coexistence of Magnetism and Superconductivity in Potassium-Doped Europium di Iron di Arsenide (Eu1-x KxFe2As2)

Abstract

This thesis investigates the influence of magnetic ordering on superconductivity in the compound. Utilizing a comprehensive model Hamiltonian and employing the equation of motion approach within Green's function formalism; we explore the intricate interplay between various parameters governing these phenomena. Our analysis reveals a remarkable exponential increase in the superconducting transition temperature (TC) with the coupling strength (λ), indicating enhanced superconductivity driven by greater electron density and electron phonon interaction. Additionally, we observe a decline in the superconducting order parameter with increasing temperature, highlighting the dominant role of thermal energy in suppressing superconductivity. Furthermore, heightened magnetic order is found to disrupt superconductivity, while increased spin order sustains magnetic behavior even at elevated temperatures. Theoretical calculations for Tc demonstrate excellent agreement with experimental values, validating our theoretical framework and providing valuable insights into the complex relationship between superconductivity and magnetism.