Evolution of superconductivity and corresponding electronic structure in pressurized Nb3Sn

Abstract

The studies on superconductors under extreme conditions offer valuable insights for assessing their potential in new applications. Nb₃Sn, an intermetallic alloy with an A15 structure, is a key commercial superconductor known for its high critical current and magnetic field tolerance. Here, we systematically investigated the physical properties of Nb₃Sn under high pressures. Our findings reveal that superconductivity in Nb₃Sn remains robust up to $\sim$142 GPa, demonstrating remarkable stability despite a gradual suppression of $T_c$ with increasing pressure. First-principles calculations indicate that the pressure-dependent superconducting behavior is primarily driven by variations in the density of states of Nb’s d-electrons, particularly contributions from the $d_{x^2-y^2}$ and $d_{z^2}$ orbitals. Furthermore, we predict the potential for synthesizing Nb₃Sn films and demonstrate that biaxial strain induced by suitable substrates can preserve their superconducting properties. This comprehensive study not only enhances our understanding of Nb₃Sn’s superconducting mechanism under high pressure but also opens new avenues for its application in advanced superconducting technologies.