Defect and anisotropic gap induced quasi-one-dimensional modulation of local density of states in YBa$_2$Cu$_3$O$_{7-\delta}$

TL;DR

This paper explores how defects and anisotropic gaps in YBa₂Cu₃O₇−δ influence local density of states, revealing quasi-one-dimensional modulations linked to Fermi surface nesting, with implications for understanding high-temperature superconductivity.

Contribution

It proposes a theoretical model explaining defect-induced stripe structures and anisotropic gap effects in YBCO, connecting STM, ARPES, and neutron scattering observations.

Findings

Identification of quasi-one-dimensional LDOS modulations at higher biases.

Correlation between anisotropic gap, defects, and Fermi surface nesting.

Potential unification of experimental observations across techniques.

Abstract

Motivated by recent angle-resolved photoemission spectroscopy (ARPES) measurement that superconducting YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) exhibits a $d_{x^2-y^2} + s$-symmetry gap, we show possible quasi-one-dimensional modulations of local density of states in YBCO. These aniostropic gap and defect induced stripe structures are most conspicuous at higher biases and arise due to the nesting effect associated with a Fermi liquid. Observation of these spectra by scanning tunneling microscopy (STM) would unify the picture among STM, ARPES, and inelastic neutron scattering for YBCO.