Controllable suppression of the unconventional superconductivity in bulk and thin-film Sr2RuO4 via high-energy electron irradiation

Abstract

In bulk Sr2RuO4, the strong sensitivity of the superconducting transition temperature Tc to nonmagnetic impurities provides robust evidence for a superconducting order parameter that changes sign around the Fermi surface. In superconducting epitaxial thin-film Sr2RuO4, the relationship between Tc and the residual resistivity ρ0, which in bulk samples is taken to be a proxy for the low-temperature elastic scattering rate, is far less clear. Using high-energy electron irradiation to controllably introduce point disorder into bulk single-crystal and thin-film Sr2RuO4, we show that Tc is suppressed in both systems at nearly identical rates. This suggests that part of ρ0 in films comes from defects that do not contribute to superconducting pairbreaking and establishes a quantitative link between the superconductivity of bulk and thin-film samples. Published by the American Physical Society 2024