Unidirectional anisotropy in cubic FeGe with antisymmetric spin-spin-coupling

Abstract

We report strong unidirectional anisotropy in bulk polycrystalline B20 FeGe measured by ferromagnetic resonance spectroscopy. Bulk and micron-sized samples were produced and analytically characterized. FeGe is a B20 compound with inherent Dzyaloshinskii-Moriya interaction. Lorenz microscopy confirms a skyrmion lattice at $190\text{K}$ in a magnetic field of 150 mT. Ferromagnetic resonance was measured at $276\text{K}\pm 1\text{K}$, near the Curie temperature. Two resonance modes were observed, both exhibit a unidirectional anisotropy of $K=1153{\text{J/m}}^3\pm 10{\text{J/m}}^3$ in the primary, and $K=28{\text{J/m}}^3\pm 2{\text{J/m}}^3$ in the secondary mode, previously unknown in bulk ferromagnets. Additionally, about 25 standing spin wave modes are observed inside a micron-sized FeGe wedge, measured at room temperature ($\sim 293$ K). These modes also exhibit unidirectional anisotropy.

References in corpus (7)

• Skyrmion Lattice in a Chiral Magnet
• Observation of room temperature magnetic skyrmions and their current-driven dynamics in ultrathin Co films
• Spin-Wave Propagation in the Presence of Interfacial Dzyaloshinskii-Moriya Interaction
• Direct observation of the Dzyaloshinskii-Moriya interaction in a Pt/Co/Ni film
• Precursor phenomena at the magnetic ordering of the cubic helimagnet FeGe
• The Unusual Nature of Confined Modes in a Chiral System
• A unified description of collective magnetic excitations

Cited by in corpus (1)

• Confined dipole and exchange spin waves in a bulk chiral magnet with Dzyaloshinskii-Moriya interaction