Upgrading the quantum computer

Abstract

As she walks around the lab of Rigetti Computing, quantum engineer Sabrina Hong strains to make her voice heard over a loud pumping noise. It’s the heartbeat of helium refrigerators cooling down the Berkeley, California–based start-up’s quantum computers. To perform optimally, these machines need to run below –273.14 °C (10 mK)—colder than outer space. Whoosh, supercold liquid helium is pumped in. Whoosh, warmed helium is pushed out. “I love that sound,” Hong says. It means the company’s two commercial quantum computers are up and running, at the ready for customers. Rigetti and other firms in the quantum computing business, including IBM and Google, allow customers to access their machines over the cloud and perform calculations. The pumping sound also means that the machines are ready for Hong and other engineers on the Rigetti team. She wants to improve quantum computers’ performance and would like to try out some test chips