SKM 2023 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 42: Quantum dots: Growth

HL 42.6: Vortrag

Donnerstag, 30. März 2023, 16:45–17:00, POT 151

Statistical Analysis of the Spatial Distribution of MBE Grown InAs Quantum Dots on GaAs(100) — •Normen Auler, Akshay Kumar Verma, Ziyang Zhang, and Dirk Reuter — Universität Paderborn, Warburger Str. 100, 33098 Paderborn

Self-assembled InAs quantum dots (QDs) have been intensively studied as model systems for strong three-dimensional confinement over decades and gained considerable interest for applications in quantum technology. The growth by molecular beam epitaxy has been widely studied. In this contribution, we discuss the spatial distribution of InAs QDs grown by solid source molecular beam epitaxy on a GaAs(100) surface for different QD densities. Therefore, we determine the distribution of nearest-neighbor distances from atomic force microscope (AFM) images and compare them to simulated random distributions. We find good agreement under the assumption of a "denuded" zone of ca. 40 nm around each quantum dot center. This means that the QDs are basically randomly distributed as one would expect from the statistical nature of the nucleation process. The diameter of the denuded zone can either be interpreted as the average geometrical diameter of the QDs or the geometrical diameter plus a small distance due to a repelling interaction between QDs mediated by the strain field. We cannot decide this from our experimental data because AFM overestimates the geometrical diameter. For very low quantum dot densities as often required for single dot experiments, it is very difficult to obtain experimental data with statistical significance, whereas simulations can give insight into the spatial distribution.