Interferometric Method for Direct Measurement of the Effective Mass in Two-Dimensional Systems

We have developed a method of determining the effective mass of charge carriers in a two-dimensional electron system (2DES) based on the phase analysis of the radiation transmitted through the 2DES. This measurement technique is demonstrated in the experiments with a high-quality 2DES in $\mathrm{In}\mathrm{As}$/$\mathrm{Al}\mathrm{Sb}$ and $\mathrm{Ga}\mathrm{As}$/$(\mathrm{Al},\mathrm{Ga})\mathrm{As}$ heterostructures. Furthermore, we find that the proposed approach gives compatible results with the cyclotron resonance spectroscopy method.