Defect and anisotropic gap-induced quasi-one-dimensional modulation of the local density of states of YBa₂Cu₃O_7-δ

Motivated by recent angle-resolved photoemission spectroscopy (ARPES) measurement that superconducting YBa₂Cu₃O _7-δ (YBCO) is consistent with a d_x2-y2+s-symmetry gap, we show possible defect-induced quasi-one-dimensional modulations of the local density of states in YBCO. These stripelike structures are more conspicuous at higher measuring biases of the scanning tunneling microscopy (STM). Observation of these STM spectra would provide a unified picture of anisotropic gap on YBCO among STM, ARPES, and inelastic neutron scattering measurements.