Modulated Helical Metals at Magnetic Domain Walls of Pyrochlore Iridium Oxides

TL;DR

This paper investigates the unique metallic states at magnetic domain walls in pyrochlore iridium oxides, revealing their topological helical spin textures and potential for spintronic applications.

Contribution

It introduces a symmetry-adapted effective Hamiltonian to describe emergent metallic domain walls with topological and helical spin textures in pyrochlore iridium oxides.

Findings

Emergent metallic domain walls with topological helical spin textures.

Detectable signatures in anomalous Hall and optical conductivities.

Potential for spin-current generation and half-metallic conduction.

Abstract

Spontaneous symmetry breakings, metal-insulator transitions, and transport properties of magnetic-domain-wall states in pyrochlore iridium oxides are studied by employing a symmetry adapted effective hamiltonian with a slab perpendicular to the (111) direction of the pyrochlore lattice. Emergent metallic domain wall, which has unconventional topological nature with a controllable and mobile metallic layer, is shown to host Fermi surfaces with modulated helical spin textures resembling Rashba metals. The helical nature of the domain-wall Fermi surfaces is experimentally detectable by anomalous Hall conductivity, circular dichroism, and optical Hall conductivity under external magnetic fields. Possible applications of the domain-wall metals to spin-current generation and "half-metallic" conduction are also discussed.