Scientists twist tiny crystals to control electricity

Researchers have developed a technique that allows them to carve complex three dimensional nanodevices directly from single crystals. To demonstrate its power, they sculpted microscopic helices from a magnetic material and found that the structures behave like switchable diodes. Electric current prefers one direction, but the effect can be flipped by changing the magnetization or the twist of the helix. The findings show that geometry itself can be used as a tool for electronic design.