1. Institute of PhysicsChinese Academy of Sciences 100190 Beijing China
2. School of Physical SciencesUniversity of Chinese Academy of Sciences 100049 Beijing China
3. Beijing Key Laboratory of Quantum DevicesKey Laboratory for the Physics and Chemistry of Nanodevicesand Department of ElectronicsPeking University Beijing 100871 China
4. Collaborative Innovation Center of Quantum Matter 100190 Beijing China
5. CAS Key Laboratory of Soft Matter PhysicsBeijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
6. Division of Solid State PhysicsLund University Box 118 S‐22100 Lund Sweden
7. State Key Laboratory for Mesoscopic Physicsand Collaborative Innovation Center of Quantum MatterSchool of PhysicsPeking University Beijing 100871 China