Spin amplitude wave due to dipole-quadrupole hybridization in spin-1 pyrochlore magnets

TL;DR

This paper investigates how dipole-quadrupole hybridization in spin-1 pyrochlore magnets leads to amplitude-modulated spin-density waves, revealing a novel phase with coexisting liquid and solid magnetic properties.

Contribution

It introduces a new mechanism where anisotropic exchange and single-ion anisotropy induce quadrupolar moments, resulting in a hybrid spin state in pyrochlore magnets.

Findings

Identification of quadrupolar moments on specific sublattices.

Proposal of a hybrid dipolar-quadrupolar spin-density wave phase.

Insight into exotic insulating magnetic phases.

Abstract

We explore the quantum pseudospin-1 pyrochlore magnet featuring Fe$^{2+}$-based spinel oxides that addresses the formation of amplitude-modulated spin-density waves. We propose that the relatively small spin-orbit coupling and the small extra crystal field splitting in these materials create anisotropic exchange interactions and strong single-ion anisotropy, respectively, whose interplay becomes the source of quadrupolar moments selectively appearing on certain sublattices, leading to a spatially modulated hybrid of dipolar and quadrupolar moments. This mechanism represents the possibility of insulating magnets to form an exotic phase with coexisting liquid-solid properties.