The choice of substrate orientation for semiconductor quantum dot circuits offers opportunities for tailoring spintronic properties such as g-factors for specific functionality. Here, we demonstrate the operation of a few-electron double quantum dot circuit fabricated from a (110)-oriented GaAs quantum well. We estimate the in-plane electron g-factor from the profile of the enhanced inter-dot tunneling (leakage) current near-zero magnetic field. Spin blockade due to Pauli exclusion can block inter-dot tunneling. However, this blockade becomes inactive due to hyperfine interaction mediated spin flip-flop processes between electron spin states and the nuclear spin of the host material. The g-factor of absolute value ∼0.1 found for a magnetic field parallel to the direction is approximately a factor of four lower than that for comparable circuits fabricated from a material grown on widely employed standard (001) GaAs substrates and is in line with reported values determined by purely optical means for quantum well structures grown on (110) GaAs substrates.
Electron g-factor determined for quantum dot circuit fabricated from (110)-oriented GaAs quantum well
T. Nakagawa, S. Lamoureux, T. Fujita, J. Ritzmann, A. Ludwig, A. D. Wieck, A. Oiwa, M. Korkusinski, A. Sachrajda, D. G. Austing, L. Gaudreau; Electron g-factor determined for quantum dot circuit fabricated from (110)-oriented GaAs quantum well. J. Appl. Phys. 7 April 2022; 131 (13): 134305. https://doi.org/10.1063/5.0086555
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