Engineering single-atom dynamics with electron irradiation
Cong Su1,2*, Mukesh Tripathi3 , Qing-Bo Yan4 , Zegao Wang5,6, Zihan Zhang7 , Christoph Hofer3 , Haozhe Wang2 , Leonardo Basile8 , Gang Su7,9, et al.
1 Department of Nuclear Science and Engineering and Department of MaterialsScience and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
2 Research Lab of Electronics (RLE), Massachusetts Institutes of Technology, Cambridge, MA 02139, USA.
Atomic engineering is envisioned to involve selectively inducing the desired dynamics of single atoms and combining these steps for larger-scale assemblies. Here, we focus on the first part by surveying the single-step dynamics of graphene dopants, primarily phosphorus, caused by electron irradiation both in experiment and simulation, and develop a theory for describing the probabilities of competing configurational outcomes depending on the postcollision momentum vector of the primary knock-on atom. The predicted branching ratio of configurational transformations agrees well with our atomically resolved experiments. This suggests a way for biasing the dynamics toward desired outcomes, paving the road for designing and further upscaling atomic engineering using electron irradiation.