A team led by Zheng Hao and Jia Jinfeng from the Tsung-Dao Lee Institute and the School of Physics and Astronomy at Shanghai Jiao Tong University, in collaboration with partners from Nanyang Technological University and other institutions, has achieved the tuning and observation of a quantum phase transition in the mixed-valence regime at the single-atom scale. Using a dilution-refrigerator scanning tunneling microscope (STM) and the tip-induced band bending (TIBB) effect, the team continuously tuned the energy level and charge state of a single Fe impurity embedded in a Bi2Te3/NbSe2 heterostructure, driving the system into the mixed-valence regime for the first time. They observed the continuous evolution of Yu-Shiba-Rusinov (YSR) states as the doping energy level shifted, as well as the complete quantum phase transition process. The related results were published under the title "Atomic-scale visualization of quantum ph".