Quantum Transport and Sub-Band Structure of Modulation-Doped GaAs/AlAs Core-Superlattice Nanowires

Irber, Dominik M.; Seidl, Jakob; Carrad, Damon J.; Becker, Jonathan; Jeon, Nari; Loitsch, Bernhard; Winnerl, Julia; Matich, Sonja; Döblinger, Markus; Tang, Yang; Morkötter, Stefanie; Abstreiter, Gerhard; Finley, Jonathan J.; Grayson, Matthew; Lauhon, Lincoln J. and Koblmüller, Gregor (2017): Quantum Transport and Sub-Band Structure of Modulation-Doped GaAs/AlAs Core-Superlattice Nanowires. In: Nano Letters, Vol. 17, No. 8: pp. 4886-4893

Abstract

Modulation-doped III-V semiconductor nano wire (NW) heterostructures have recently emerged as promising candidates to host high-mobility electron channels for future high-frequency, low-energy transistor technologies. The one-dimensional geometry of NWs also makes them attractive for studying quantum confinement effects. Here, we report correlated investigations into the discrete electronic sub-band structure of confined electrons in the channel of Si 5 doped GaAs GaAs/AlAs core superlattice NW heterostructures and the associated signatures in low-temperature transport. On the basis of accurate structural and dopant analysis using scanning transmission electron microscopy and atom probe tomography, we calculated the sub-band structure of electrons confined in the NW core and employ a labeling system inspired by atomic orbital notation. Electron transport measurements on top-gated NW transistors at cryogenic temperatures revealed signatures consistent with the depopulation of the quasi-one-dimensional sub-bands, as well as confinement in zero-dimensional-like states due to an impurity-defined background disorder potential. These findings are instructive toward reaching the ballistic transport regime in GaAs-AlGaAs based NW systems.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 1530-6984
• Language: English