Spin resonance in EuTiO3 probed by time-domain gigahertz ellipsometry

Area of Science:

• Condensed Matter Physics
• Materials Science
• Magnetism

Background:

• Understanding magnetic properties of materials is crucial for developing advanced optical devices.
• Europium titanate (EuTiO3) exhibits interesting magnetic and dielectric properties.
• Faraday rotation is a key magneto-optical effect with applications in optical isolators and modulators.

Purpose of the Study:

• To investigate purely magnetic spin resonance in EuTiO3.
• To achieve and record high Faraday rotation using a novel technique.
• To determine the complex refractive index and understand the underlying magnetic interactions.

Main Methods:

• Magneto-optical gigahertz time-domain ellipsometry was employed to probe the material.
• Transmission measurements of linearly polarized light were conducted.
• The complex refractive index (n=√ϵμ) was mapped in the gigahertz to terahertz range.

Main Results:

• A purely magnetic spin resonance was observed in EuTiO3.
• A record high Faraday rotation of 590°/mm at 1.6 T was achieved for 1 cm wavelengths.
• Strong resonant absorption and large dichroism for circularly polarized radiation were observed due to magnetic dipole transitions.

Conclusions:

• The study demonstrates a new pathway for achieving significant Faraday rotation through magnetic resonance.
• EuTiO3 shows potential for applications in high-frequency magneto-optical devices.
• The novel ellipsometry technique provides valuable insights into the magnetic and optical properties of materials.