Zeeman Splitting of Zero‐Dimensional Heavy‐Hole States in a Strongly Strained Ge Quantum Well

The method of magnetotunneling spectroscopy has been used for experimental probing of heavy‐hole impurity states in Si/Ge double‐barrier heterostructures in magnetic field up to 18 Tesla. The impurities were located in a strained Ge quantum well with a thickness of four monolayers. We have observed a giant anisotropy of Zeeman splitting for these zero‐dimensional systems. The splitting was measured as a function of angle between the external magnetic field and the quantum well plane. A complete suppression of the splitting takes place when the magnetic field is oriented parallel to the sample surface and quantum well plane, while in the perpendicular field the observed splitting is maximal.