1. Interuniversity Microelectronics Center (IMEC) 1 , 3001 Leuven, Belgium
2. KU Leuven, QSP Division 2 , Celestijnenlaan 200 D - Box 2414, 3001 Leuven, Belgium
3. Univ. Grenoble Alpes, CNRS, Institut Néel 3 , 38042 Grenoble, France
4. KU Leuven, ESAT-INSYS Division 4 , Kasteelpark Arenberg 10, 3001 Leuven, Belgium
5. Universiteit Antwerpen, Departement of Physics 5 , Groenenborgerlaan 171, 2020 Antwerp, Belgium