Angle-resolved photoemission from cuprates with static stripes

Twenty five years after discovery of high-temperature superconductivity (HTSC) in La2−xBaxCuO4 (LBCO), the HTSC continues to pose some of the biggest challenges in materials science. Cuprates are fundamentally different from conventional superconductors in that the metallic conductivity and superconductivity are induced by doping carriers into an antiferromagnetically ordered correlated insulator. In such systems, the normal state is expected to be quite different from a Landau-Fermi liquid – the basis for the conventional BCS theory of superconductivity. The situation is additionally complicated by the fact that cuprates are susceptible to charge/spin ordering tendencies, especially in the low-doping regime. The role of such tendencies on the phenomenon of superconductivity is still not completely clear. Here, we present studies of the electronic structure in cuprates where the superconductivity is strongly suppressed as static spin and charge orders or “stripes” develop near the doping level of x = 1/8 and “outside” of the superconducting dome, for x < 0.055. We discuss the relationship between the “stripes”, superconductivity, pseudogap and the observed electronic excitations in these materials.

► Correlation between stripes, QP properties and superconductivity observed in 214 cuprates.
► At the onset of superconductivity (x ∼ 0.05), the diagonal stripes give away to superconductivity.
► Appearance of static parallel stripes at x = 1/8 suppresses superconductivity.
► Spectral gap in non-superconducting samples at x = 1/8 resembles superconducting gap.
► Parallel stripes seem to enhance pairing, but destroy phase coherence.