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.
The research will be useful in the world of sensing -- which often requires extraordinarily low temperatures, very close to absolute zero. Normally, these temperatures are achieved by the use of liquid helium in huge, complex and costly apparatus.
Ullom hopes that his research, published in Applied Physics Letters, could allow these temperatures to be reached in a much simpler, more compact, package.
This article was originally published by WIRED UK
