Renormalization of the electron g factor in the degenerate two-dimensional electron gas of ZnSe- and CdTe-based quantum wells

• Published in: Physical review. B 2020-09, Vol.102 (12), p.1, Article 125306
• Main Authors: Zhukov, E. A., Mantsevich, V. N., Yakovlev, D. R., Kopteva, N. E., Kirstein, E., Waag, A., Karczewski, G., Wojtowicz, T., Bayer, M.
• Format: Article
• Language: English
• Subjects: Cadmium tellurides; Electron density; Electron gas; Magnetic fields; Photoexcitation; Quantum wells; Spin-orbit interactions
• ISSN: 2469-9950; 2469-9969
• DOI: 10.1103/PhysRevB.102.125306

The effective electron g factor, geff, is measured in a two-dimensional electron gas (2DEG) in modulation-doped ZnSe- and CdTe-based quantum wells by means of time-resolved pump-probe Kerr rotation. The measurements are performed in magnetic fields applied in the Voigt geometry, i.e., normal to the optical axis parallel to the quantum well plane, in the field range 0.05–6 T at temperatures 1.8– 50 K . The geff absolute value considerably increases with increasing electron density ne. geff changes in the ZnSe-based QWs from +1.1 to +1.9 in the n e range 3 × 1010 − 1.4 × 1012 cm−2 and in the CdTe-based QWs from −1.55 down to −1.76 in the ne range 5 × 109 − 3 × 1011 cm−2. The modification of geff reduces with increasing magnetic field, increasing temperature of lattice and 2DEG, the latter achieved by a higher photoexcitation density. A theoretical model is developed that considers the renormalization of the spin-orbit coupling constant of the two-dimensional electrons by the electron-electron interaction and takes into account corrections to the electron-electron interaction in the Hubbard form. The model results are in good agreement with experimental data.