Robustness of d-Density Wave Order to Nonmagnetic Impurities

TL;DR

This study investigates how nonmagnetic impurities affect coexisting d-density wave and d-wave superconducting orders, revealing that DDW order is more robust to impurities than DSC order due to inhomogeneity effects.

Contribution

It demonstrates that DDW order remains stable in the presence of impurities, unlike DSC order, using Bogoliubov-de Gennes calculations to analyze spatial variations.

Findings

DDW order is more robust to impurities than DSC order.

Inhomogeneities in DDW are strongly correlated with density variations.

Disorder significantly affects the density of states.

Abstract

Effect of finite density of nonmagnetic impurities on a coexisting phase of d-density wave (DDW) order and d-wave superconducting (DSC) order is studied using Bogoliubov-de Gennes (BdG) method. The spatial variation of the inhomogeneous DDW order due to impurities has a strong correlation with that of density, which is very different from that of DSC order. The length scale associated with DDW is found to be of the order of a lattice spacing. The nontrivial inhomogeneities are shown to make DDW order much more robust to the impurities, while DSC order becomes very sensitive to them. The effect of disorder on the density of states is also discussed.