1 National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.
2 Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich GmbH, Jülich, Germany.
3 Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden.
4 Graduate School of Pure & Applied Science and Faculty of Pure & Applied Science, University of Tsukuba, Tsukuba, Japan.
5 Central Facility for Electron Microscopy, RWTH Aachen University, Aachen, Germany.
6 National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China. [email protected].
In Fig. 1 of the version of this Letter originally published, the word 'Subtract' was missing from the green box to the left of panel f. This has now been corrected in all versions of the Letter.