Understanding Spin Configuration in the Geometrically Frustrated Magnet TbB$_{4}$: a Resonant Soft X-ray Scattering Study

TL;DR

This study uses resonant soft x-ray scattering to elucidate the spin reorientation mechanism in the geometrically frustrated magnet TbB$_{4}$, revealing complex interactions between spins and crystal symmetry that inform quantum spin liquid research.

Contribution

It provides the first detailed analysis of spin configuration and reorientation mechanism in TbB$_{4}$ using RSXS, highlighting the interplay between spin and crystal symmetry.

Findings

Spin reorientation occurs upon cooling due to spin-crystal symmetry interactions.

RSXS signals depend on temperature, photon energy, and polarization.

The mechanism is dominated by spin and symmetry interplay, not quadrupole orbit effects.

Abstract

The frustrated magnet has been regarded as a system that could be a promising host material for the quantum spin liquid (QSL). However, it is difficult to determine the spin configuration and the corresponding mechanism in this system, because of its geometrical frustration (i.e., crystal structure and symmetry). Herein, we systematically investigate one of the geometrically frustrated magnets, the TbB$_{4}$ compound. Using resonant soft x-ray scattering (RSXS), we explored its spin configuration, as well as Tb's quadrupole. Comprehensive evaluations of the temperature and photon energy / polarization dependences of the RSXS signals reveal the mechanism of spin reorientation upon cooling down, which is the sophisticated interplay between the Tb spin and the crystal symmetry rather than its orbit (quadrupole). Our results and their implications would further shed a light on the search for possible realization of QSL.