Diamagnetic coefficients and g-factors of InAs/InGaAlAs quantum dashes emitting at telecom wavelengths

Abstract

Semiconductor nanostructures of various material systems are heavily researched for information processing applications as single-photon sources for communication and as a spin memory for storage. Here, exciton, electron, and hole properties in single InAs/InP asymmetric quantum dots (quantum dashes) emitting in a broad spectral range from 0.8 to above 1 eV are studied experimentally and theoretically. Experiments using magneto-microphotoluminescence allowed us to determine g-factor tensor components and diamagnetic coefficients. The growth-axis exciton g-factor is in a 0.0–2.9 range with a constant hole g-factor of 4.5 and variation governed by electron contribution. The in-plane g-factor is more stable with the size of the nanostructure exhibiting values of around −0.7 and −1.6 for holes and electrons, respectively. The diamagnetic coefficients are 13 and 5μeVT2 in the growth and in-plane directions, respectively. Simulations based on the eight-band k⋅p model qualitatively reproduce the key experimental features, including the vanishing of the inverse fine-structure splitting of bright exciton at around 3 T, making these structures prospective for the generation of entangled photons.