Peanut butter and chocolate. Rice and soy sauce. Milk and cookies. When two good things get together, they can create something even better.
That’s the case with quantum information—the marriage of quantum physics and computing theory. The National Institute of Standards and Technology (NIST) has contributed to much of its history and is helping to shape its future.
“We have been there from the beginning,” says NIST physicist Carl Williams, who has directed much of the agency’s efforts in this field since the early 2000s. “We can now see quantum information moving from a purely scientific field to a technological one.”
In the not-too-distant future, a quantum version of a traditional computer could perform sophisticated simulations that could lead to new drugs and high-tech materials. In the longer term, a more powerful quantum computer, if it can be built, could quickly break the digital security that currently protects online banking and shopping. But not to fear: post-quantum encryption could also protect data from a quantum cyberattack launched by an adversary. And quantum random-number generators could produce nature’s most unpredictable digits on the fly, for encryption and other uses.
Many other quantum information applications could potentially appear in the marketplace in the next decade. They include advanced quantum sensors that could reveal underground oil and mineral deposits. Quantum information technology could lead to new portable navigation devices that soldiers could use to find their way even when GPS networks are jammed or knocked out.
NIST has been at the center of this quantum information revolution, thanks to its broad scientific expertise and a culture that fosters interaction between professionals in many fields.
Notably, partnerships between NIST and public universities have created dedicated research institutes that combine the vast potential of curiosity-driven research with the resources of the federal government.
JILA, a joint institution of NIST and the University of Colorado Boulder, has been doing research in quantum information since the early days of the field in the 1990s.
And founded in 2006, the Joint Quantum Institute (JQI), a partnership between NIST, the University of Maryland, and the Laboratory for Physical Sciences, was set up by researchers including Nobel laureate Bill Phillips, who saw the need for a dedicated, collaborative institution.
“It was really so that scientists could study quantum phenomena from all different sides, and learn to share ideas and speak each other’s languages to push the field forward even faster,” says Gretchen Campbell, co-director of JQI. The quantum revolution is now spreading beyond universities and federal labs. Companies are investing hundreds of millions of dollars in a race to build quantum computers, which promise to disrupt industries and dramatically improve technology.
“Google, Intel, Microsoft, IBM, and so forth have quantum teams, and they're actually trying to build hardware,” says Chris Monroe, a JQI fellow, professor of physics at the University of Maryland, and co-founder of the quantum information company IONQ. “It’s a very exciting time.”
As the field transitions from academic labs to industry, NIST is continuing its leadership by supporting the researchers working on the software side of the quantum revolution. Hardware is only half the story, and algorithms and other software-related research are the other side of the coin.
In order to build a community of multidisciplinary expertise in these fields, NIST and the University of Maryland partnered again in 2014 to form the Joint Center for Quantum Information and Computer Science (QuICS). Whereas JQI studies the physics of quantum information, QuICS focuses on mathematics and computer science.
Because quantum information integrates so many fields—including mathematics, computer science, quantum mechanics, and engineering—there are typically gaps in the understanding of any one expert.
Institutes such as QuICS, JQI and JILA don’t just produce multidisciplinary collaborations. They are also helping to train the next generation of workers in the field. This is especially necessary given some of the mind-bending features of quantum information, like quantum entanglement.
“So, while traditionally, a place like JQI would have graduated mostly academics, an increasing fraction of our students are actually going into industry these days,” says Gretchen Campbell, co-director of JQI. “We’re training young people who are going out and pushing the frontiers of quantum research in both the private and public sectors.”
Quantum mechanics revolutionized the 20th century. It explains the workings of very small objects such as atoms, and things that have very small amounts of energy such as photons, or individual packets of light. It brought about the laser, tiny computer chips and energy-efficient LEDs. It spawned new sectors of the economy such as the semiconductor industry, in which global worldwide sales reached $339 billion in 2016 and grew by 21 percent in the second quarter of 2017 compared to the same period in 2016, according to the Semiconductor Industry Association.
Computing theory explores how efficiently mathematical problems can be solved with computers, specifically through the use of algorithms, or a set of steps that a computer takes to solve a problem. The theory has been in development ever since the 1930s when Alan Turing developed a model of computation that has come to be known as the Turing machine. In the 1960s, NIST contributed to some fundamental notions, such as the mathematical theory of efficient algorithms, that helped make these fields what they are today.
Starting in the 1970s and 1980s, researchers began to explore the potential of quantum information in detail. Theorists proposed hypothetical quantum versions of computers, encryption devices and communications schemes.
“Computing is a physical process, and if you think about it in those terms, it opens up all sorts of new insights in both computing and the physical sciences,” says Ron Boisvert, a mathematician at NIST.
Like a bar of chocolate smashing into a jar of peanut butter, quantum physics and computing theory collided spectacularly in 1994. That year, Peter Shor, then a mathematician at AT&T Bell Laboratories, realized that a quantum version of a computer, if it could be built, could do something dramatically better than regular computers.
Shor created an algorithm, designed to run on a future quantum computer, that could quickly crack the encryption schemes used for banking and other sensitive transactions. His quantum algorithm could rapidly factor the very large numbers that are used to scramble data into the numbers that serve as their secret keys. This bombshell discovery launched a race that bloomed into a new field.
But as researchers have long known, quantum computers would be much more than devices that break old technology. They could help scientists better understand important complex materials such as high-temperature superconductors, which conduct energy without resistance. They could advance artificial intelligence by quickly finding patterns in big data. They could identify new efficiencies in supply chains, and help transportation companies more easily identify the shortest routes when making many stops.
And beyond direct practical applications on Earth, simulations about quantum computers could even help us obtain new insights about the universe.