Tuesday, March 12, 2013
Wired reports: [edited]
Nanotechnology researchers have built a microscopic fridge that can cool objects millions of times more massive than itself.
The prototype solid-state device takes advantage of the way quantum physics operates in micro- and nanostructures to cool comparatively-vast objects to sub-cryogenic temperatures.
Project leader Joel Ullom said that the cooling power is equivalent to a window-mounted air conditioner cooling a building the size of the Lincoln Memorial in Washington DC, and added: "It's one of the most flabbergasting results I've seen."
He explained: "We used quantum mechanics in a nanostructure to cool a block of copper. The copper is about a million times heavier than the refrigerating elements. This is a rare example of a nano- or microelectromechanical machine that can manipulate the macroscopic world."
It works by sandwiching together a metal, an insulating layer just a single nanometre thick, and a superconductor. When a voltage is applied, the electrons with the most energy (the "hottest" ones) tunnel through the insulator to the superconductor, making the temperature in the metal drop dramatically.