Magneto-optical study of Ga0.47In0.53As–InP under hydrostatic pressure

Abstract

Far-infrared and interband photoconductivity measurements were carried out on high-purity Ga0.47In0.53As. All the measurements were performed at 4.2 K or below in magnetic fields up to 16 T. Hydrostatic pressure of up to 10 kbar (1 bar = 105 Pa) was also applied on the sample during the experiments, using the liquid clamp cell technique. Our work was mainly focussed on the study of conduction-band nonparabolicity. The dependence of the electron effective mass toward energy was accurately determined from our cyclotron resonance measurements and compared with a theoretical description that includes nonparabolicity and magnetopolaron effects. We find that the nonparabolicity coefficient and its variation with pressure are in agreement with the theoretical predictions based on the Kane model, when the contribution of magnetopolaron effect is included in the data analysis. These results are correlated with those obtained in the interband measurements, which have been analysed within a Pidgeon–Brown approach. Some interesting data concerning impurity states were also obtained in our far-infrared photoconductivity measurements. A much richer set of Zeeman-split impurity-related peaks were recorded, as compared with previously published results. The influence of pressure, nonparabolicity, and the magnetopolaron effect on the position of these peaks will be briefly discussed.