A long-sought device able to produce a beam of 'T-rays' that could revolutionise airport security and medical scans has been created by persuading normally independent quantum junctions to work together.
The new gadget produces terahertz waves, or T-rays, which are sandwiched between infrared light and microwaves in the electromagnetic spectrum. Many researchers are trying to use them because, like microwaves, they can pass through many materials such as clothing, but provide much higher resolution images.
But making terahertz waves is tricky. Lasers and microwave emitters can be pushed out of their usual ranges to emit them. But there remains a "terahertz gap" in the middle, between about 0.5 and 2 terahertz, which no device has been able to fill.