Magnetic Anisotropy of a One-Dimensional Electron System

We have discovered a novel anisotropy in a quasi-one-dimensional electronic system in the presence of a magnetic field. The density of states changes dramatically when a magnetic field is applied along different axes of the sample. Further, we do not observe spin splitting of one-dimensional levels in magnetic fields up to 20 T, indicating that enhancement of the Landé $g$ factor is also anisotropic. These results provide new insight into the underlying properties of quantum-confined electrons.