Using a scanning tunneling microscope (STM), it is not possible to physically "cut" a single atom from a source material. However, the STM can manipulate individual atoms by precisely positioning the microscope's probe tip near the atom of interest.
The process of manipulating and dislodging an atom using an STM involves the following steps:
Preparation: The STM probe tip, which is typically made of a sharp metal tip, is brought into close proximity with the surface of the source material. The material should be conductive for STM imaging and manipulation.
Scanning: The STM scans the surface of the material by maintaining a constant current or constant height mode. This scanning allows for the visualization of the surface topography at an atomic scale.
Positioning: Once a desired atom is located on the surface, the STM probe tip is positioned precisely above or near the atom using the fine control mechanisms of the microscope. This positioning requires careful adjustments of the tip position in the x, y, and z directions.
Tunneling current: The STM operates based on the principle of quantum tunneling. A small voltage is applied between the tip and the surface, creating a tunneling current between them. The strength of the current depends on the distance between the tip and the surface.
Manipulation: By adjusting the tip-sample distance and the tunneling current, it is possible to exert forces on individual atoms. The tip can push or pull the atom, enabling manipulation within certain limits.
It's important to note that the manipulation of individual atoms using an STM requires careful control and precision due to the sensitivity of the process. While an STM can enable the precise positioning and manipulation of atoms, it is not designed to physically separate or detach an atom from the source material in a way that allows it to be collected separately.