Current flowing through a single silicon atom can be made to decrease with increasing voltage, potentially allowing the integration of a new type of component into microelectronic circuits.
Negative differential resistance (NDR) refers to current decreasing as voltage increases, contrary to a normal resistor. The phenomenon is useful in electronics, and now a research team has demonstrated a reliable form of single-atom NDR and has explained in detail how it works. To verify their model, the team used a scanning tunneling microscope in a new way—they measured the time it takes for electrons to hop onto a single atom and showed that this time is critical for the NDR effect. The work opens the door to integration of NDR into microelectronic devices.