Hypothesis of two-dimensional stripe arrangement and its implications for the superconductivity in high-Tccuprates

Abstract

The hypothesis that holes doped into high-Tc cuprate superconductors organize themselves in two-dimensional (2D) array of diagonal stripes is discussed, and, on the basis of this hypothesis, a new microscopic model of superconductivity is proposed and solved. The model describes two kinds of hole states localized either inside the stripes or in the antiferromagnetic domains between the stripes. The characteristic energy difference between these two kinds of states is identified with the pseudogap. The onset of superconductivity is caused by the interaction, which is assumed to be mediated by the transverse fluctuations of stripes. The superconducting (SC) order parameter predicted by the model has two components, whose quantum phases exhibit a complex dependence on the the center-of-mass coordinate. The model predictions for the tunneling characteristics and for the dependence of the critical temperature (Tc) on the superfluid density show good quantitative agreement with a number of experiments. The model, in particular, predicts that the SC peaks in the tunneling spectra are asymmetric, only when ∆/Tc > 4, where ∆ is the SC gap. It is also proposed that, at least in some high-Tc cuprates, there exist two different superconducting states corresponding to the same doping concentration and the same critical temperature. Finally, the checkerboard pattern in the local density of states observed by scanning tunneling microscopy in Bi2Sr2CaCu2O 8+δ is interpreted as coming from the states localized around the centers of stripe elements forming the 2D superstructure.

Spin dynamics near the critical doping in weakly superconducting underdopedYBa2Cu3O6.35Stock1, Buyers2, Yamani3 et al. 2008Phys. Rev. B

“…A related model of stripes and superconductivity addresses the different kinds of hole states. 74 Nonetheless our observation of a continuous evolution to a subcritical 3D spin pattern, without a transition in temperature, is at odds with a picture of physically separated islands, or of a cluster spin glass, and certainly with phase separation, for which the highly organized 3D spin pattern along [0 0 1] would not occur. In particular the continuous transfer of spectral weight from the relaxational to the central mode, as discussed later (Fig.…”

Pseudogap and Fermi surface in the presence of a spin-vortex checkerboard for 1/8-doped lanthanum cuprates

“…1. The above matter has been extensively discussed on the basis of both theoretical arguments and experimental evidence [31][32][33][34][35][36][37]. On the theoretical side, the situation was, in particular, analysed on the basis of the Landau-type expansion in powers of the order parameter [37].…”

“…Various experiment-based arguments in favor of either stripes or checkerboards for lanthanum cuprates have been put forward in Refs. [31][32][33][34][35][36][37]40], but the issue has not been settled either. This issue is elusive not only in lanthanum cuprates, but also for the yittrium-based and other cuprate families -see, e.g., Refs.…”

Two-dimensional geometry of spin excitations in the high-transition-temperature superconductor YBa2Cu3O6+x

“…A theoretical description in this framework should also account for the observed energy dependence of the anisotropy. An alternative approach would be to consider a two-dimensional arrangement of charged domain walls 1,15 .…”