g-factor engineering with InAsSb alloys toward zero band gap limit

Band gap is known as an effective parameter for tuning the Landé Formula Presented factor in semiconductors and can be manipulated in a wide range through the bowing effect in ternary alloys. In this work, using the recently developed virtual substrate technique, high-quality InAsSb alloys throughout the whole Sb composition range are fabricated and a large Formula Presented factor of Formula Presented at the minimum band gap of Formula Presented eV, which is almost twice that in bulk InSb, is found. Further analysis to the zero gap limit reveals a possible gigantic Formula Presented factor of Formula Presented with a peculiar relativistic Zeeman effect that disperses as the square root of magnetic field. Such a Formula Presented-factor enhancement toward the narrow gap limit cannot be quantitatively described by the conventional Roth formula, as the orbital interaction effect between the nearly triply degenerated bands becomes the dominant source for the Zeeman splitting. These results may provide insights into realizing large Formula Presented factors and spin-polarized states in semiconductors and topological materials.