Scientists at the RIKEN Center for Emergent Matter Science have developed a groundbreaking nanofabrication technique that allows complex three-dimensional devices to be carved directly from single-crystal materials with unprecedented precision. Using focused ion beam technology, the research team sculpted microscopic helical structures from a magnetic crystal composed of cobalt, tin, and sulfur (Co₃Sn₂S₂). These tiny helices acted as switchable diodes, meaning they preferentially conduct electric current in one direction — and crucially, this directional preference could be flipped by altering the magnetization or changing the twist of the structure itself.