Spin dynamics in the pseudogap state: Phase fluctuation versus d-density wave

Abstract

The dynamical spin susceptibility in the pseudogap phase of high- Tc cuprates is examined for two different scenarios: the phase fluctuation (PF) of pairing and the d-density wave (DDW) order. In the PF scenario, while the resonant feature of the spin response at Q = (ππ) is preserved at weak PF, the feature is lost as the fluctuation is increased. The dispersion of the spin response in the PF scenario is simply a broadened version of the spectrum in the d-wave superconducting (DSC) state at all the strengths of PFs being discussed. In the DDW scenario, there is no spin resonant mode found at the AFM wave vector in nature, and the spin response exhibits the almost dispersionless feature markedly different from that in the PF scenario. As far as the spin dynamics in the pseudogap state is concerned, our results support the scenario that the pseudogap phenomenon is derived from a distinct normal-state order. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.