Dynamical charge and spin density wave scattering in cuprate superconductors
We show that a variety of spectral features of high- T c cuprates can be understood on the basis of the coupling of charge carriers to some kind of dynamical order that we exemplify in terms of fluctuating charge and spin density waves. Two theoretical models that capture different aspects of such a dynamical scattering are investigated. The first approach leaves the ground state in the disordered phase but couples the electrons to bosonic degrees of freedom, corresponding to the quasi-singular scattering associated with closeness to an ordered phase. The second, more phenomological approach starts from the construction of a frequency-dependent order parameter that vanishes for small energies. Both theories capture scanning tunneling microscopy and angle-resolved photoemission experiments that suggest the protection of quasi-particles close to the Fermi energy but the manifestation of long-range order at higher frequencies.