Checkerboard superconducting order and antinodal Bogoliubov quasiparticle interference

Abstract

Numerical study of momentum-dependent gap function is presented to make clear the origin of superconductivity in copper oxides. We claim that antinodal region with pronounced nesting feature of the Fermi contour gives rise to superconducting pairing with large momentum under screened Coulomb repulsion. Such a pairing results in both spatial checkerboard pattern of the superconducting state below T c and a gapped state of incoherent pairs in a broad temperature range above T c . We explain the momentum dependence of the coherent spectral weight detected in angleresolved photoemission spectroscopy and predict antinodal Bogoliubov quasiparticle interference other than observed in the nodal region.

Chiral d-wave superconductor with nonzero center-of-mass pair momentum

“…Recently introduced concept of SC pairing with large pair momentum under screened Coulomb repulsion 11 offers an explanation of principal features of cuprate superconductors: 1) a checkerboard real-space ordering observable in the SC state 12 can be directly related to the pair momentum, comparable with reciprocal lattice spacing; 13 2) pseudogap (PG) state 14 with a broad region of SC fluctuations above the transition temperature T c can be explained by a rise of quasi-stationary states of pairs with large momentum due to real-space oscillations of the screened Coulomb potential; 15 3) high-energy effects observable in optical experiments 16 can be related to the electron-hole asymmetry that becomes apparent in the SC state of the cuprates.…”

“…To solve the gap equation numerically, we approximate the interaction energy by a simple step function of κ = k − k ′ . 13 Step length in the direction of K is limited by the length of the nested segment of the FC. In the direction perpendicular to K, left step at κ l corresponds to phonon-mediated decrease in energy taking into account the forward scattering effect 18 whereas right step at κ r reflects the fact that values of the order parameter turn out to be very small at all points distant from the FC.…”

“…Therefore, the order parameter turns out to be weakly sensitive to κ r . 13 We use the electron dispersion that conforms to the FC observable in hole doped cuprates,…”

“…Recently obtained numerical solution to the gap equation 13 corresponding to a symmetric superposition of two running waves is presented in Fig. 1 (only left half of the Brillouin zone is shown) in which the momenta of the running waves ±K are chosen as directed along k y axis.…”

Perturbed Angular Correlations Studies in the HgBa2CaCu2O6+δ high-TC Superconductor

“…Although some aspects related to the properties of these compounds are generally accepted, the topic of inhomogeneous distribution of charge carriers is still in debate [4]. Moreover, evidence of organized patterns were reported and terms like phase separation, stripes and checkerboard patterns are concepts still heavily discussed [5][6][7]. From all high-T C superconductors, the Hg-based family [8][9][10] is one of the most promising systems due to their simple tetragonal crystalline structure and the highest superconducting transition temperatures (T C ).…”