Symmetry, distorted band structure, and spin-orbit coupling of group-III metal-monochalcogenide monolayers

摘要: The electronic structure of (group-III) metal-monochalcogenide monolayers exhibits many unusual features. Some, such as the unusually distorted upper valence-band dispersion we describe a ``caldera,'' are primarily result purely orbital interactions. Others, including spin splitting and wave-function mixing, directly driven by spin-orbit coupling. We employ elementary group theory to explain origin these properties, use tight-binding model calculate phenomena enabled them, band-edge carrier effective $g$ factors, optical absorption spectrum, conduction electron orientation, relaxation-induced upper-valence-band population inversion polarization mechanism.