Structural characterization and magnetotransport in Ge/Si quantum dots

Artificially ordered quantum dot (QD) arrays may create unique functionalities such as cluster qubits and spintronic bandgap systems.\footnote{C. E. Pryor, M. E. Flatte, and J. Levy, Applied Physics Letters \textbf{95}, 232103 (2009)} We fabricate directed self-assembled Ge/SiC/Si arrays with fine control over QD size and spatial arrangement on the sub-35 nm length scale for this purpose. The formation, thermal stability, and structure of the QDs are studied extensively with transmission electron microscopy (TEM) and atomic force microscopy (AFM).\footnote{C. Petz, D. Yang, J. Levy and J. Floro, Journal of Material Research \ (JMR-2012-0430)} Magnetotransport measurements through the QD arrays shows a diamagnetic shift that depends on the dots' spatial configuration. We attribute this configuration dependence to the interaction of the electrons between different QDs.