Quantum resonances in the valence bands of germanium. II. Cyclotron resonances in uniaxially stressed crystals

作者：J. C. Hensel, Kohei Suzuki · 发表于：Physical review. B, Solid state · 年份：1974 · DOI：10.1103/physrevb.9.4219 · 被引用次数：224 · 研究领域：Silicon Nanostructures and Photoluminescence、Semiconductor materials and interfaces、Silicon and Solar Cell Technologies

As a consequence of the degeneracy of the Ge valence bands at $\stackrel{\ensuremath{\rightarrow}}{k}=0$, the lowest Landau levels are anomalously spaced, so the cyclotron resonances of holes under "quantum" conditions, $\frac{\ensuremath{\hbar}\ensuremath{\omega}}{k\ensuremath{\Theta}}>1$ ($\ensuremath{\Theta}$ being the temperature), give rise to complex line spectra. We report here measurements of these "quantum" spectra taken at 53 GHz and 1.2\ifmmode^\circ\else\textdegree\fi{}K in samples of Ge subjected to uniaxial, compressive stresses which lower the cubic symmetry and remove the valence-band degeneracy. The effect of the stress $T$ on the positions of the quantum lines permits their identification and also provides a direct measurement of the uniaxial deformation potentials: ${D}_{u}=3.32\ifmmode\pm\else\textpm\fi{}0.20$ eV and ${D}_{u}^{\ensuremath{'}}=3.81\ifmmode\pm\else\textpm\fi{}0.25$ eV. At large stresses, as the energy surfaces assume ellipsoidal shape, the quantum lines arrange themselves into four line series identifiable by ${M}_{J}=\ifmmode\pm\else\textpm\fi{}(\frac{1}{2}),\ifmmode\pm\else\textpm\fi{}(\frac{3}{2})$ for $T\ensuremath{\parallel}[001]$ and $T\ensuremath{\parallel}[111]$. With increasing stress the lines converge to two series limits corresponding to the "classical" effective masses of the two split bands, $|{M}_{J}|=(\frac{1}{2}), (\frac{3}{2})$. For stress along each of the principal crystallographic directions---[001], [111], and [110]---t...