Complementary response of static spin-stripe order and superconductivity to non-magnetic impurities and pressure in cuprates

Cuprate high-temperature superconductors (HTSs) have complex phase diagrams with multiple competing ordered phases. Understanding to which degree charge, spin, and superconducting orders compete or coexist is paramount for elucidating the microscopic pairing mechanism in the cuprate HTSs. In this talk, i will report some novel results of muon-spin rotation (µSR), neutron Scattering and magnetization experiments on non-magnetic Zn impurity and hydrostatic pressure effects on the static spin-stripe order and superconductivity in the La214 cuprates [1]. Remarkably, it was found that in these systems the spin-stripe ordering temperature T_so decreases linearly with Zn doping y and disappears at y ≈ 4%, demonstrating the high sensitivity of static spin-stripe order to impurities within a CuO₂ plane. Moreover, T_so is suppressed in the same manner as the superconducting transition temperature T_c by Zn impurities. We also observed the same pressure evolution of both T_c and T_so in La_2−xBa_xCuO₄, while there is an antagonistic pressure evolution of magnetic fraction and superfluid density. These results indicate that static spin-stripe order and SC pairing correlations develop in a cooperative fashion in La214 cuprates.

[1] Z. Guguchia et. al., PRB 94, 214511 (2016). PRL 119, 087002 (2017).