Angularly quantized spin rotations in hexagonal LuMnO3

TL;DR

This paper reports the observation of angularly quantized spin rotations in hexagonal LuMnO3, revealing discrete spin excitations linked to lattice symmetry, with potential applications in high-density spin-based information storage.

Contribution

It introduces a model explaining angularly quantized spin rotations in LuMnO3, connecting lattice symmetry to discrete spin excitations observed via light scattering.

Findings

Angularly quantized spin excitations at 60°, 120°, and 180°.

Spin rotations linked to the triangular lattice symmetry.

Potential for high-density spin information storage.

Abstract

Optical control of the spin degree of freedom is often desired in application of the spin technology. Here we report spin-rotational excitations observed through inelastic light scattering of the hexagonal LuMnO3 in the antiferromagnetically (AFM) ordered state. We propose a model based on the spin-spin interaction Hamiltonian associated with the spin rotation of the Mn ions, and find that the spin rotations are angularly quantized by 60, 120, and 180 degrees. Angular quantization is considered to be a consequence of the symmetry of the triangular lattice of the Mn-ion plane in the hexagonal LuMnO3. These angularly-quantized spin excitations may be pictured as isolated flat bubbles in the sea of the ground state, which may lead to high-density information storage if applied to spin devices. Optically pumped and detected spin-excitation bubbles would bring about the advanced technology of optical control of the spin degree of freedom in multiferroic materials.