Tsu-Jae Liu

At the IEEE International Electron Devices Meeting (IEDM) in San Francisco last December, researchers discussed their efforts to find ways of increasing the capacity of quantum computers, a tricky challenge because any solution needs to work at near absolute zero temperatures. Berkeley research led by engineering professor Tsu-Jae King Liu was presented by her graduate student Xiaoer Hu. They developed micrometer-scale electromechanical relays as ultralow-power alternatives to transistors, and made the happy discovery that the relays worked better at 4 K than at room temperature. That's because oxygen can interfere with conductivity at room temperature, while oxygen gets frozen out at cryogenic temperatures. "We didn't suspect ahead of time that these devices would operate so well at cryogenic temperatures," Professor Liu says. "In retrospect, we should have."