Effect of uniaxial strain on the superconducting state of Sr₂RuO₄

The symmetry of the superconducting order parameter offers information on the mechanism of Cooper pair formation in unconventional superconductors. Until recently, Sr₂RuO₄ was a leading candidate for spin-triplet superconductivity. Recent evidence on the spin part of the order parameter suggests spin-singlet pairing with an even parity superconducting gap. Additional measurements on Sr₂RuO₄ suggests a two-component order parameter. Such a state may exhibit two transition temperatures under non-zero strain, which may be observable by magnetic susceptibility measurements. In this talk, we report on a scanning SQUID susceptometry measurement in which we map the diamagnetic response of Sr₂RuO₄ as a function of temperature and uniaxial strain with micron-scale spatial resolution. We also present the dependence of the superconducting transition temperature (T_c) on uniaxial strain. We observe both quadratic and linear cusp components in T_c vs strain, where the strength between each component is sensitive to position on the sample.