Two Atom Transistor

LN12557 - The fabrication of single-atom transistors is a breakthrough which is now possible both by top-down and bottom up approaches. Using standard microelectronics techniques we made a transistor where the current is controlled by the fine tuning of the ionization of two phosphorus atoms connected in series. Following single-atom devices, this 2-atom transistor is the next step towards controlled atomic functionalities in electronics. Here we use the discrete ground level of one donor as a sharp energy filter to probe the levels of a second donor. Our results show that the energy spectrum for electrons bounded to a phosphorus atom in a silicon nano device is reminiscent but differs slightly from the spectrum of an isolated donor in a bulk silicon crystal. The large energy separation (10 meV) between the ground and first excited state arises from the sharp atomic confinement potential is a good opportunity for clean atomic orbital's manipulation.