Atomic force microscopy for imaging, identification and manipulation of single atoms

Abstract

Measuring tiny interatomic forces between tip and sample has been an important challenge in the development of atomic force microscopy (AFM). Present force sensitivity achieved by a frequency modulation (FM) technique allows us to obtain atomic resolution routinely using FM-AFM. We applied the capability to measure the chemical bond between two atoms to identify the chemical species on surfaces. The chemical bonding force can also be used for single atom manipulation at room temperature. Recently, these AFM capabilities have led to the creation of various artificial nanostructures atom-by-atom, such as atomic clusters. By AFM characterization combined with scanning tunneling microscopy (STM), we found that some clusters work as atomic switches, which can be controlled by atomic force as well as carrier injection.