It turns out that when you shrink a Vacuum transistor to absolutely tiny dimensions, you can recover some of the benefits of a vacuum tube and dodge the negatives that characterized their usage. According to a report in IEEE Spectrum, vacuum transistors can draw electrons across the gate without needing a physical connection between them. Make the vacuum area small enough, and reduce the voltage sufficiently, and the field emission effect allows the transistor to fire electrons across the gap without containing enough energy to energize the helium inside the nominal “vacuum” transistor. According to researchers, they’ve managed to build a successful transistor operating at 460GHz — well into the so-called “Terahertz Gap,” which sits between microwaves and infrared energy. The “gap” refers to the fact that we have a limited number of devices that can generate this frequency and only a handful of experimental applications for this energy band.

via How Vacuum Tubes, New Technology Might Save Moore’s Law – HotHardware.