  We report Raman scattering experiments on the strongly correlated electron
system NaxCoO2 with x= 0.71 and ordered Na vacancies. In this doping regime,
NaxCoO2 exhibits a large and unusual thermopower and becomes superconducting
upon hydration. Our Raman scattering data reveal pronounced low energy
fluctuations that diverge in intensity at low temperatures. Related to these
fluctuations is a drastic decrease of an electronic scattering rate from 50 to
3 cm-1. This observation is quite different from the behavior of Na disordered
samples that have a larger and temperature independent scattering rate.
Simultaneously with the evolution of the scattering rate, phonon anomalies
point to an increasing out-of-plane coherence of the lattice with decreasing
temperature. These observations may indicate the condensation of spin polarons
into an unusual, highly dynamic ground state.
