As helium-3 runs scarce, researchers seek new ways to chill quantum computers.

This article focuses on the critical role and challenges of dilution refrigerators, which use helium-3 to achieve ultracold temperatures near absolute zero, enabling quantum technologies such as quantum computers. Bluefors, a Finnish company, leads in manufacturing these refrigerators, but the scarcity and high cost of helium-3—primarily sourced from decaying tritium in nuclear weapons—pose supply risks as quantum computing scales up. Researchers and companies are exploring alternative cooling methods, including magnetic cooling, on-chip electronic cooling using superconducting traps, and photonic cooling with light-emitting diodes, aiming to reduce reliance on helium-3 and improve scalability. While dilution refrigerators remain essential today, hybrid approaches combining multiple cooling technologies may shape the future of quantum cryogenics. [Extracted from the article]