導電性シート近似を用いた半導体薄膜のテラヘルツ磁気光学スペクトロスコピックエリプソメトリのモデリング

We present a simplified model for analyzing the reflection coefficients of anisotropic semiconductor thin films in terahertz magneto-optical ellipsometry. Derived from electromagnetic boundary conditions, the model is valid when the film thickness is much smaller than the wavelength. Its applicability is demonstrated through terahertz time-domain spectroscopic ellipsometry of two doped GaAs thin films under an external magnetic field. The approach allows direct extraction of sheet conductivity spectra and accurately reproduces the observed magneto-optical response, offering a non-invasive method for characterizing various thin-film materials.