DYNAMICAL SPIN SUSCEPTIBILITY IN THE UNDERDOPED CUPRATE SUPERCONDUCTORS: DDW STATE AND INFLUENCE OF ORTHORHOMBICITY

摘要

We present a study of the dynamical spin susceptibility in the so-called id-density wave (DDW) state in application to the pseudogap phase of underdoped cuprates. In particular we analyze the structure of the dynamical spin susceptibility in the DDW phase at the antiferromagnetic wave vector Q = (π, π). We find that similar to the superconducting state a resonance peak forms. However, away from Q it shows nearly no dispersion. We also analyze the spin response in the coexisting DDW and d_(x~2-y~2)-wave superconducting (DSC) states and discuss the peculiar features of the resonance peak dispersion. Furthermore, we investigate the influence of various tight-binding parameters and the orthorhombic distortions on the robustness of the features discussed.