1. Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
2. Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
3. Laboratorio de Microscopı́as Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, 50018 Zaragoza, Spain
4. Fundación ARAID, Av. de Ranillas 1-D, 50018 Zaragoza, Spain
5. Departamento de Fı́sica Aplicada, Universidad de Zaragoza, 50009 Zaragoza, Spain
6. Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
7. National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China