Scientists have demonstrated the first reproducible, controllable silicon transistors that are turned on and off by the motion of individual electrons. The experimental devices, designed and fabricated at NTT Corp. of Japan and tested at NIST, may have applications in low-power nanoelectronics, particularly as next-generation integrated circuits for logic operations (as opposed to simpler memory tasks).
Colorized micrograph of three tunable gates across an electrical channel in a single electron tunneling (SET) transistor.
The transistors, described in the Jan. 30, 2006, issue of Applied Physics Letters,* are based on the principle that as device sizes shrink to the nanometer range, the amount of energy required to move a single electron increases significantly. This makes it possible to control individual electron motion and current flow by manipulating the voltage applied to barriers, or "gates," in the electrical circuit. At negative voltage, the transistor is off; at higher voltage, the transistor is turned on and individual electrons file through the circuit, as opposed to thousands at a time in a conventional device.
This type of innovative transistor, called a "single-electron tunneling" (SET) device, is typically made with a metal "wire" interrupted by insulating barriers that offer a rigid, narrow range of control over electron flow. Silicon devices, by contrast, have barriers that are electrically "tunable" over a wider operating range, offering finer, more flexible control of the transistors on/off switch. Particular voltage levels are applied across the barriers, to manipulate charge, as a means of encouraging or impeding electron flow. Silicon-based devices also allow fabrication using standard semiconductor technology. Until now, however, no silicon SET transistor designs have been reported that are reproducible and controllable.
Laura Ost | EurekAlert!
UNH scientists help provide first-ever views of elusive energy explosion
16.11.2018 | University of New Hampshire
NASA keeps watch over space explosions
16.11.2018 | NASA/Goddard Space Flight Center
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
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Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
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On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
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