New Research on Miniature Electronic Switch Single Atom Transistor

[ Instrument R & D of Instrument Network ] Transistors composed of only a few atoms or even a single atom are now expected to become the basis of a new generation of computers with unparalleled storage and processing capabilities. To realize the full potential of these microtransistors (microelectronic switches), researchers must find a way to replicate these extremely difficult-to-manufacture components in large quantities.

The electronic switch refers to the operating unit that uses electronic circuits and power electronic devices to achieve circuit on and off. It includes at least one controllable electronic drive device, such as thyristors, transistors, field effect transistors, thyristors, and relays. However, in actual use, electronic switches mainly refer to wall switches such as touch switches, sensor switches, voice control switches, and wireless switches.

The National Institute of Standards and Technology (NIST) has collaborated with researchers from the University of Maryland to gradually develop methods for producing atomic-level devices. This research team led by NIST has become the second team in the world to manufacture single-atom transistors, and has produced a series of single-electron transistors that perform atomic-level control of device geometry.

The researchers showed that they can precisely adjust the rate at which individual electrons pass through physical gaps or electrical barriers in transistors. This quantum phenomenon (called quantum tunneling) only becomes critical when the gap is extremely small (for example in microtransistors). Precise control of quantum tunneling is important because it enables transistors to "entangle" or interconnect in a quantum mechanical manner, and opens up new possibilities for creating qubits that can be used in quantum computing.

Figure: Schematic diagram of the method of manufacturing single atom transistor developed by NIST

The research results were published in the latest issue of "Advanced Functional Materials" magazine. The researchers believe that this is an extremely important result. Manufacturing single-atom transistors is a difficult and complicated process. Now NIST has taken a critical step and gained valuable experience. Other research teams can also avoid unnecessary repeated trials and mistakes.

The researchers demonstrated that they can precisely control the rate at which individual electrons cross the atomic tunnel barrier in a single-electron transistor. They produced a series of single-electron transistors that were identical except for the size of the tunneling gap. Current measurements show that by increasing or decreasing the gap between transistor components by less than 1 nanometer (one billionth of a meter), individual electrons can be precisely controlled in a predictable way through the transistor.

Since quantum tunneling is critical to the construction of all quantum devices such as qubits, controlling the ability to pass a single electron in a single pass is a major achievement. In addition, as the number of circuits installed on microcomputer chips increases and the gaps between components continue to shrink, understanding and controlling the effects of quantum tunneling will become more important.