1. Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, 215123 Suzhou, People’s Republic of China
2. Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
3. Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
4. Diamond Light Source, Harwell Science and Innovation Campus, OX11 0DE Oxfordshire, United Kingdom