It’s looking official: A quantum computer designed and operated by Google may have solved a problem impossible to solve by today’s classical computers. This astonishing conclusion comes from today’s official release, and we now wait for all aspects of the story to be evaluated by the scientific community. In recent weeks the anticipation and hype were rising daily, but why do we actually care?
John Preskill from Caltech coined the term “quantum supremacy” about seven years ago to describe a specific point in the development of quantum computers when calculations impossible or impractical for classical computers will be done with quantum bits, or qubits, rather than with bits. Minutes will be needed — rather than time comparable to the age of the Universe — to compute and predict new materials, drugs and chemicals, and to solve complex simulations of climate, stars, building blocks of matter, or even the origins of life.
Skeptics claimed over the years that this point would never be reached because of a multitude of challenges plaguing quantum computing and related to noise, error corrections, scaling, connectivity or decoherence, where the environment around the qubits causes the quantum system to fail. Some said quantum mechanics, because of problems inherent in interpreting results, might never provide tangible advances over classical computing.
If confirmed, this apparent breakthrough sets a new scene, with quantum computing elevated directly from a hyped-up expectation to a productive technique. We also can expect quantum computing to drive accelerated development in quantum communications, sensing and simulation. Once the news is confirmed, quantum supremacy will become a truly transformative force driving a worldwide technological revolution.
A lot needs to happen before we get there. Current advances are demonstrated on one specific platform based on Josephson junctions, devices made of two superconducting layers separated by a barrier and requiring extremely low temperatures. In order to proliferate widely, quantum computers will have to operate at room temperature. Some approaches address that challenge, though they have yet to produce a fully functioning quantum computer. Designers also need to learn how to battle decoherence, correct for noise, scale up, and fully connect all qubits in quantum computers, as well as efficiently connect with classical control electronics and data transfer lines.
That research is underway. To build on this critical mass of discovery and to maintain U.S. leadership in the area, the National Quantum Initiative Act was established in December 2018 and the White House developed the National Strategic Overview for Quantum Information Science. These provide a path forward based on a “science first” approach, focusing on stimulating transformative and fundamental research. It is a coordinated all-of-government approach, stimulating close collaboration among industry, academia and government. With industry eager to transition quantum computing from the lab to store shelves, more fundamental research is underway at universities and national labs through the help of agencies such as the Department of Energy, National Institute of Standards and Technology, and the National Science Foundation. NSF has supported, and continues to support, many of the fundamental research efforts that are leading to the current breakthroughs and continuing to fuel further industrial aspirations.
Formidable challenges make such focused approaches at national scale a must. Critically, we need to think strategically about the missing qualified workforce. Researchers developing quantum technology today came from one of several distinct fields, while a skilled quantum workforce requires a fusion of traditional education and a “quantum intuition” that enables someone to instinctively distinguish quantum behaviors from classical phenomena. Many of us — especially kids, who have grown up with such technology — have “classical intuition,” the ability to use classical computers instinctively. Nothing like this exists for quantum. Getting there will require improved curricula, broader training and a set of specific skills required by the emerging quantum industry: the convergent combination of quantum mechanics, electronics, engineering and coding.
With such progress, the next decade of development is set to be enchanting, with breakthroughs feeding off each other. For example, quantum computers of the future promise to help solve ultimate materials problems. On the other hand, we need to solve materials problems to achieve proliferation of quantum computers. Which will come first? We will be watching this race closely.
Tomasz Durakiewicz is program director for Condensed Matter Physics at the National Science Foundation, Division of Materials Research, and since February 2019 has served as staff associate, Office of the Assistant Director, in the agency’s Directorate for Mathematical and Physical Sciences. Durakiewicz has co-authored more than 170 peer-reviewed publications, more than 210 conference abstracts and six patents, and he has presented more than 60 invited talks. For more than a decade prior to his service at NSF, Durakiewicz was a materials researcher at the Department of Energy’s Los Alamos National Laboratory.