Freiburg 2019 – wissenschaftliches Programm
FM 84.19: Poster
Donnerstag, 26. September 2019, 16:30–18:30, Tents
Hybrid Devices of Spin-photon Interfaces for Singlet-triplet Quantum Dots — •Zheng Zeng1, David Fricker1, Arne Ludwig2, Marcel Schmidt2, Chao Zhao1, Hendrik Bluhm3, and Beata Kardynał1 — 1Peter Grünberg Institute 9, Forschungszentrum Jülich, 52425 Jülich, Germany — 2Lehrstuhl für Angewandte Festkörperphysik, Ruhr- Universität Bochum, 44780 Bochum, Germany — 3JARA-Institute for Quantum Information, RWTH Aachen University, 52074 Aachen, Germany
Connecting quantum processors over long distances using photon qubits would enable more complex quantum computing architectures and quantum networks. Recently a protocol to transfer a quantum state from a photonic qubit to a singlet-triplet spin qubit in GaAs/AlGaAs heterostructure has been theoretically demonstrated. In practice, the coherent transfer is facilitated by a hybrid device where a GaAs/AlGaAs gate-defined double quantum dot (GDQD) is tunnel coupled to a self-assemble quantum dot (SAQD), in which a conversion between a photon state and a spin state takes place. In this contribution we discuss fabrication techniques to achieve the precise alignment of both types of QDs both in energy as well as in space, which is essential for the device operation. We fabricate front- and back-gates to enable tuning the energy levels of the quantum dots. We discuss the method to align the gates of the GDQD to a SAQD. Further we explore methods of QDs growth to minimize the impact on the GDQDs. In particular we compare the performance of strain-free droplet QDs with high quality Stransky-Krastanov QDs in the hybrid devices.