Berlin 2018 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 33: Poster Session III
HL 33.28: Poster
Wednesday, March 14, 2018, 17:30–19:30, Poster F
Towards electrostatically defined Quantum Dots in ZnSe — •Christian Julien Kamphausen1, Arne Hollmann1, Felix Hartz1, Lars Reiner Schreiber1, Johanna Janßen2, Torsten Rieger2, and Alexander Pawlis2 — 1JARA - Institute for Quantum Information, RWTH Aachen University, Germany — 2Peter Grünberg Institute 9 and JARA - FIT, Forschungszentrum Jülich GmbH, Germany
ZnSe is a promising material for realizing electrostatically defined electron spin qubits combining both long coherence and optical activity. Unlike the current materials (Ga,Al)As and SiGe, our ZnSe/(Zn,Mg)Se quantum wells exhibit neither valley splitting nor a nuclear magnetic field if isotopically purified combining their strengths. As the effective mass of ZnSe is three times higher compared to GaAs, small gate patterns are required for single electron trapping.
Therefore, we demonstrate lift-off gate pattern for double quantum dots with feature size of less than 20 nm on Si substrates, which are sufficient for our ZnSe/(Zn,Mg)Se heterostructure according to simulations. In order to avoid electrical noise from doping, we implant dopants below ohmic contacts and heal/activate them by annealing. Heating ZnSe appears to be problematic due to the loss of Zn, which compensates our n-doping. Therefore, we present our studies on annealing in a Zn atmosphere using different implantation energies and species.