Observation of spin and charge stripe correlations in La_2-x-yEu_ySr_xCuO₄

The role of co-existing spin and charge (‘stripe’) orders in the La-based 214 cuprate superconductors has been a topic of enduring interest, and one with renewed relevance. Often presented as a prototypical stripe material, the family La_2-x-yEu_ySr_xCuO₄ (LESCO) has been explored far less than other stripe candidates, with spin correlations almost completely unstudied to date. In this talk, we will present the results of our recent neutron and soft x-ray scattering studies of single crystals of LESCO grown at Illinois. These data imply the existence of parallel stripe order near 1/8 Sr-doping below critical temperatures T_SO = 40K and T_CO = 80K for spin and charge correlations, respectively. We will further discuss the measured temperature and Sr-doping dependence, as well as recent bulk magnetization measurements which reveal a strongly anisotropic Meissner response consistent with the decoupling of superconductivity between CuO₂ planes. The collective results will be discussed in the context of pair-density-wave theories and the coupling between superconductivity and alternate orders in the cuprates.