Lars Peeters | Searcharxiv

arXiv2026

Bismuth-substituted Lutetium Iron Garnet Films with Giant Visible-Range Magneto-Optical Sensitivity

Magneto-optical materials are indispensable across modern physics, serving as the foundation for precision magnetic sensing, nonreciprocal photonics, and optical isolation technologies. The continual pursuit of materials with high Verdet constants has driven the development of garnet-based compounds exhibiting giant magneto-optical sensitivity. In this work, we report the growth and comprehensive magneto-optical characterization of bismuth-substituted lutetium iron garnet (LuBiIG), a material that combines the large spin-orbit coupling of bismuth with the lattice stability of lutetium iron garnet. LuBiIG films with thicknesses between 85-220nm were grown by pulsed laser deposition and characterized at room temperature over the 500-820nm wavelength range. The films exhibit an exceptionally high Verdet constant of up to -1.37e8 degree/meter/Tesla, peaking in the visible spectral range near 520nm. These results position LuBiIG as a highly sensitive magneto-optical material suitable for advanced cryogenic detection and hybrid quantum applications.

cond-mat.mtrl-sci↗

arXiv2025

Magnetic and structural properties of epitaxial Er-substituted yttrium iron garnet films grown by pulsed laser deposition

Er-substituted yttrium iron garnet (Er:YIG) holds the potential of combining the low magnetic damping of YIG with the telecom-band optical transitions of $\text{Er}^{3+}$ ions, making it a suitable material for hybrid optomagnonic devices and microwave-to-optical quantum transduction. We report the epitaxial growth of $\text{Er}_{x}\text{Y}_{3-x}\text{Fe}_{5}\text{O}_{12}$ films with $x=0.008-0.20$ on (111)-oriented gadolinium gallium garnet (GGG) substrates using pulsed laser deposition. X-ray diffraction, reciprocal space mapping, and scanning transmission electron microscopy confirm single-phase, fully coherent growth with atomically sharp interfaces across the entire substitution range. Magnetometry reveals a gradual decrease in saturation magnetization with increasing Er content, consistent with antiparallel coupling between Er$^{3+}$ spins and the net Fe$^{3+}$ moments, along with the emergence of an in-plane uniaxial magnetic anisotropy. The ferromagnetic resonance broadens with Er concentration due to increased Gilbert damping and inhomogeneous linewidth broadening. Films with low Er content ($x=0.008$), most relevant for optomagnonic applications, retain nearly isotropic magnetization and exhibit a damping parameter only slightly higher than that of undoped YIG. These results identify growth and substitution conditions that preserve YIG's low-loss magnetic properties while introducing optical functionality, establishing Er:YIG as a viable platform for hybrid quantum magnonics and microwave-to-optical transduction.

cond-mat.mtrl-sci↗