A Zeeman study of the 1.54μm transition in molecular beam epitaxial GaAs:Er

Abstract

Er-doped GaAs grown under special molecular beam epitaxy conditions emits strong luminescence at 1.54 mu m. The dominant transition of the spectrum was found to be extremely sharp (0.04 cm^-1) at 4.2 K. Zeeman measurements on this specific transition give complicated angular dependence patterns. Analysis of data reveals monoclinic I symmetry (close to rhombic I) for the crystal field, with unexpectedly low g-factors (g_1y=2.0; g_2y=1.5) for the upper and the lower Kramers doublet states, all others being equal to zero, and the angle theta being (001) and z equal to 7 degrees . Preliminary crystal-field calculations and possible microscopic models are discussed.