Boffins build room-temperature nano transistor

A collaboration between German and US scientists has yielded a single-electron transistor with a vibrating silicon arm 200 nanometres long, just tens of nanometres across, and tipped with gold.

The transistor belongs to a class of devices known as nanoelectromechanical systems, which, according to PhysicsWeb, can be manufactured fairly routinely on a nanometre scale. Traditionally, NEM devices operate in a strong magnetic field.

The device is particularly interesting because it is relatively simple to make and - because it can be switched on with AC voltage - it operates without cryogenic cooling. The researchers say it could be very useful to fundamental research in physics, as well as having a variety of practical applications.

Dominik Scheible at the Ludwig-Maximilians University in Munich and Robert Blick at the University of Wisconsin-Madison, the researchers responsible for the device, set it up so that the gold tip of the arm sits between two electrodes.

When an AC voltage applied to one of the electrodes matches the resonance frequency of the arm - specifically between 350 and 400MHz in this example - the arm will oscillate between the electrodes. This causes a flow of electrons from the source electrode to the gold island, and from there, they are tunneled towards the drain electrode.

The researchers suggest it could improve our understanding of nanoscale behaviour, if it were tailored to study the mechanically-controlled transport of single electrons. ®

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