Physicists have designed the world’s smallest refrigerator, small enough that it can’t hold any of your food. The fridge consists of three qubits–quantum particles that act as on-off switches. These quantum particles could be ions, atoms, or subatomic particles.

Other small systems have been created, but this is the first that doesn’t rely on external mechanisms, such as sophisticated lasers. “The whole guts of the fridge, it’s all accounted for and not hidden in some macroscopic object which is really doing the work,” [coauthor Noah] Linden says. [Science News]

Kitchen refrigerators work by shuttling heat away from one area (where you store your food) and dumping it somewhere else (the coils behind). This transfer isn’t news. Fans of thermodynamics have built devices to wick away heat from one source and dump it somewhere else since the nineteenth century. The device proposed in a paper to appear in Physical Review Letters uses the same basic technique but at a much smaller scale–on the size of three qubits, connected to two “baths,” one cold (or around room temperature) and one hot.

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Many years after he revolutionized the field of physics, Albert Einstein took up a new task: inventing a better refrigerator. The 1930 appliance that he patented in partnership with a former student, Leo Szilard, had no moving parts and required no electricity, but was quickly forgotten as more efficient refrigeration technology was invented. Now, an electrical engineer has built a prototype of the forgotten Einstein fridge as part of a three-year project to develop more robust appliances that can be used in places without electricity [The Guardian].

Einstein and Szilard were reportedly spurred to inventive action by a news report of a Berlin family that died when toxic gas leaked from their refrigerator; the two physicists decided to create a system without moving parts to reduce the likelihood of accidents.

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