Low-doping anomalies in high-Tc cuprate superconductors as evidence of a spin-fluctuation-mediated superconducting state.

We present a theoretical study of the impact of spin fluctuations on electronic properties when these fluctuations are soft and strong, as in low-doped cuprates. We show that they play a triple role: they mediate d pairing, destroy the coherence of antinodal electrons, and create a spin density wave pseudogap. The competition between these effects is responsible for numerous electron anomalies close to those observed experimentally in the low-doping superconducting state.