Spin canting as a result of the competition between stripes and spirals in cuprates

TL;DR

This paper investigates how the competition between stripe and spiral magnetic states in cuprates, influenced by the extended Hubbard model parameters, leads to spin canting and complex inhomogeneous textures, explaining recent experimental observations.

Contribution

It introduces a detailed analysis of stripe and spiral ground states in cuprates, highlighting the role of the t'/t ratio and proposing a new type of stripe as a domain wall with fractional phase change.

Findings

Uniform spirals favored at large t'/t

Spin canting occurs at small doping due to stripe formation

Large |t'/t| stabilizes spirals in overdoped regime

Abstract

Based on the extended Hubbard model we calculate the energy of stripe and spiral ground states. We find that uniform spirals get favored by a large $t'/t$ ratio but are unstable at small doping towards stripes and checkerboard textures with spin canting. The structure of these inhomogeneities also depends on t'/t and the associated spin currents may induce a small lattice distortion associated with local dipole moments. We discuss a new kind of stripe which appears as a domain wall of the antiferromagnetic (AF) order parameter with a fractional change of the phase of the AF order. For large |t'/t| spirals can be stabilized under certain conditions in the overdoped regime which may explain the elastic incommensurate magnetic response recently observed in iron-codoped Bi2201 materials.