Anisotropic Time-Domain Electronic Response in Cuprates

TL;DR

This paper investigates how the anisotropic d-wave symmetry of cuprate superconductors influences their non-equilibrium electronic response to photo-excitation, revealing enhanced pair coherence in the antinodal regions.

Contribution

It provides the first detailed comparison of nodal and antinodal non-equilibrium responses in cuprates, supported by a d-wave BCS model, highlighting anisotropic effects on superconducting dynamics.

Findings

Enhanced transient signals in antinodal regions indicate increased pair coherence.

Nodal regions do not show the same level of response enhancement.

The effective d-wave BCS model supports the experimental observations.

Abstract

Superconductivity in the cuprates is characterized by spatial inhomogeneity and an anisotropic electronic gap of d-wave symmetry. The aim of this work is to understand how this anisotropy affects the non-equilibrium electronic response of high-Tc superconductors. We compare the nodal and antinodal non-equilibrium response to photo-excitations with photon energy comparable to the superconducting gap and polarization along the Cu-Cu axis of the sample. The data are supported by an effective d-wave BCS model indicating that the observed enhancement of the superconducting transient signal mostly involves an increase of pair coherence in the antinodal region, which is not induced at the node.