Figure 1 (IMAGE) Peking University Caption Figure: a) Schematic graph showing the NV-based scanning electrometry. b) and c): The experimental and simulating electric-field mapping of a sharp metal tip through the single shallow NV. d) Charge-state control of single NV by the local electric field of tip. Credit International Center for Quantum Materials, Peking University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.