Disorder Induced Stripes in d-Wave Superconductors

TL;DR

This paper investigates how disorder influences stripe phases in high-temperature cuprate superconductors, revealing that impurities can stabilize stripe order and produce universal features in the density of states.

Contribution

It demonstrates that dopant disorder can stabilize stripe phases in the t-J model, even in regimes where homogeneous phases are normally favored, using a Hartree-Fock approach.

Findings

Impurities pin unidirectional density waves.

Disorder stabilizes stripe phases in certain parameter regimes.

Density of states shows universal features with a full energy gap.

Abstract

Stripe phases are observed experimentally in several copper-based high-Tc superconductors near 1/8 hole doping. However, the specific characteristics may vary depending on the degree of dopant disorder and the presence or absence of a low- temperature tetragonal phase. On the basis of a Hartree-Fock decoupling scheme for the t-J model we discuss the diverse behavior of stripe phases. In particular the effect of inhomogeneities is investigated in two distinctly different parameter regimes which are characterized by the strength of the interaction. We observe that small concen- trations of impurities or vortices pin the unidirectional density waves, and dopant disorder is capable to stabilize a stripe phase in parameter regimes where homogeneous phases are typically favored in clean systems. The momentum-space results exhibit universal features for all coexisting density-wave solutions, nearly unchanged even in strongly disordered systems. These coexisting solutions feature generically a full energy gap and a particle-hole asymmetry in the density of states.