Quantum Computing Is Here! But Also Not Really

Wednesday was warm in Santa Barbara, California, but Google’s quantum computing labs there were pleasingly cool—colder than outer space in some spots. Three fridge-sized silver cylinders hung below crowns of ducts and cables. Inside, superconducting quantum processors were at operating temperature, a fraction of a degree above absolute zero.Googlers gazed at one of the gleaming cylinders, sporting a ring of green LEDs, with special fondness. In the early hours of the morning, the journal Nature published a peer-reviewed paper describing how the chip inside, named Sycamore, had completed in minutes a math problem estimated to require a supercomputer to work flat out for 10 millennia. Although IBM has questioned Google’s results, many researchers say they appear to represent a scientific milestone termed quantum supremacy: When a quantum computer gives the first taste of the technology’s potential by doing something beyond any conventional computer, even if on a contrived problem.
On Wednesday, Google took a victory lap. “We compare it to a Sputnik moment,” Hartmut Neven, the executive who started Google’s quantum program in 2006, told reporters, wearing a silvery jacket and boots apt for the space analogy. In an interview and blog post, Google CEO Sundar Pichai giddily likened the moment to the Wright brothers’ first flight, the first rocket to escape Earth’s gravity, and chess champion Garry Kasparov’s historic loss to a computer.Despite the mondo metaphors, Google’s quantum team didn’t have a big party planned that night. Neven said he was thinking of perhaps a small dinner. “We have a lot going on right now,” noted a more junior member of the team.

Google's quantum processor Sycamore resides in an electromagnetically shielded cryostat that keeps it cold. Photograph: Tom Simonite
The superposition of celebration and sobriety on display at Google’s quantum HQ was fitting. The company’s supremacy experiment is a signal moment in a recent burst of progress in quantum computing. Tech giants, startups, investors, and governments are plowing more money into quantum computing. Nature estimates that private firms working in quantum-related technology raised $400 million in 2017 and 2018, more than double the amount in the previous five years. At the same time, no one quite knows when today’s quantum technology, even Google’s champ Sycamore, will mature into something useful—or profitable."This is not a technology milestone, it’s a scientific milestone," says David Poulin, codirector of the quantum information program at the Canadian Institute for Advanced Research, and a professor at Université de Sherbrooke in Quebec.