Populated Domain Walls

TL;DR

This paper proposes that charge carriers in certain cuprate superconductors are localized on domain walls due to strong electron-electron interactions, offering explanations for their anomalous behaviors and methods to improve experimental detection.

Contribution

It introduces a theoretical argument that localized charge density on domain walls is plausible, supported by Hubbard model results, and suggests ways to enhance experimental signatures.

Findings

Charge density localization on domain walls is plausible due to electron-electron repulsion.

Strong short-range interactions influence the ground state energy of the system.

Proposed method to suppress wall meandering to improve neutron diffraction signatures.

Abstract

Several experiments suggest that the charge carriers in the normal state of certain cuprate superconductors reside on domain walls. In an earlier paper, we suggested that several aspects of the anomalous dynamical behavior of these materials could be explained, at least qualitatively, on this basis. Here, using results on the ground state energy of the 1-dimensional Hubbard model (soluble by Bethe ansatz techniques) as a function of charge density, we argue that a non-zero charge density localized to domain walls is a very plausible consequence of strong short-range electron-electron repulsion. We also suggest a method to suppress meandering of the walls, and thereby enhance their signature in neutron diffraction.