A step toward computing with terahertz radiation

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This week the University of Utah made an announcement that one of its research teams has been able to construct a terahertz wave guide

“We have taken a first step to making circuits that can harness or guide terahertz radiation,” says Ajay Nahata, study leader and associate professor of electrical and computer engineering. “Eventually – in a minimum of 10 years – this will allow the development of superfast circuits, computers and communications.”

If you think of a wire as a waveguide for electrons, this experiment demonstrates that there is an analogue for terahertz radiation. According to the researcher

“People have been working on terahertz waveguides for a decade,” he says. “We’ve shown how to make these waveguides on a flat surface so that you can make circuits just like electronic circuits on silicon chips.”

A bit on the electricity analogue

The design of the waveguide means that it carries terahertz radiation in the form of surface plasma waves – also known as plasmons or plasmon polaritons – which are analogous to electrons in electrical devices or photons of light in optical devices. The surface plasma waves are waves of electromagnetic radiation at a terahertz frequency that are bound to the surface of the steel foil because they are interacting with moving electrons in the metal, Nahata says.

A quick Google on this research shows a lot of “terahertz computers are coming” headlines that leave the impression these things are just around the corner, but there is much fundamental work left to be done:

“All we’ve done is made the wires” for terahertz circuits, Nahata says. “Now the issue is how do we make devices [such as switches, transistors and modulators] at terahertz frequencies?”