1. Istituto Nazionale di Ricerca Metrologica, Turin, Italy
2. Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, Perugia, Italy
3. School of Physics and Astronomy, University of Leeds, Leeds, U.K
4. Centre de Nanosciences et de Nanotechnologies (CNRS), Université Paris-Saclay, Palaiseau, France
5. Korea Research Institute of Standards and Science, Yuseong-gu, Daejeon, Republic of Korea
6. Institute of Physics, Johannes Gutenberg University of Mainz, Mainz, Germany
7. Spin-Ion Technologies, Center for Nanoscience and Nanotechnology (C2N), Palaiseau, France
8. National Institute of Standards and Technology (NIST), Boulder, CO, USA
9. Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
10. C/o Dipartimento di Fisica e Geologia, Centro Nazionale Ricerche (CNR), Istituto Officina dei Materiali—Perugia, Università degli Studi di Perugia, Perugia, Italy