Back in the late 1980s and early 1990s, Scott Bakula starred in a television show entitled “Quantum Leap.” The premise of the show involved a failed experiment which resulted in Bakula’s character, a former scientist named Sam Beckett, finding himself trapped in time. Every week Beckett was transported into the body of a different person facing a life challenge he had to overcome before moving on to the next body. If that sounds weird, it was. It was also very funny. The show was aptly named, however, because weird things do happen at the quantum level. Researchers hope to take advantage of those weird characteristics to develop a new type of computer — a quantum computer. Researchers continue to debate whether a practical, programmable quantum computer can actually be built; but, as the debate rages, some researchers continue to announce breakthroughs they claim brings that goal a step closer. Tech journalist Tom Simonite (@tsimonite) writes, “If the tech industry pulls off that, ahem, quantum leap, you won’t be getting a quantum computer for your pocket. … We could, however, see significant improvements in many areas of science and technology, such as longer-lasting batteries for electric cars or advances in chemistry that reshape industries or enable new medical treatments. Quantum computers won’t be able to do everything faster than conventional computers, but on some tricky problems they have advantages that would enable astounding progress.”[1]

What is a Quantum Computer?

In simple terms, a quantum computer is a computer that takes advantage of the fact that, at the quantum level, a quantum bit (aka qubit) can simultaneously be both a 0 and a 1 — this phenomenon is called superposition. The weirdness continues with the fact that a quantum particle can simultaneously appear to be in two places at once. This phenomenon — called entanglement — involves a pair of quantum particles linked together in a such a way that when one particle is altered its twin is instantaneously altered in exactly the same way regardless of how far apart the entangled particles may be. Professor Albert Einstein famously called entanglement “spooky action at a distance.” Because a qubit can simultaneously be both a 0 and a 1, quantum machines compute differently than traditional machines. James Norman explains, “Quantum computers can be game changers because they can solve important problems no existing computer can. While conventional computing scales linearly, QC scales exponentially when adding new bits. Exponential scaling always wins, and it’s never close. QC represents a fundamental shift in computing speed and efficiency, and the types of problems computers can solve. This allows for the successful analysis of far more complex problems. Examples include the interaction of drug molecules; vehicle driving patterns; and financial market movements and investor behavior patterns. Harnessing QC could lead to the creation of new drugs, dramatically improved hurricane forecasts, safer self-driving cars, enhanced GPS navigation, and more effective identification of stock or bond market inefficiencies.”[2]

The Goal is a Universal, Programmable Computer

Brian Hopkins, Vice President and principal analyst at Forrester, explains there are two general classes of quantum computers.[3] They are:

• Scalable, universal computers: This type of quantum computer is the Holy Grail researchers are pursuing. As Hopkins notes, “[Universal quantum computers] understand and execute logic like a classical computer, error-corrected, can solve a lot of problems without having to be specialized.”
• Specialized computers: Hopkins explains “[Specialized quantum computers] use quantum annealing for domain-specific optimization problems.” A Canadian company called D-Wave already markets this type of computer.

Here’s the challenge: Because qubits are created at the quantum level (i.e., they are very, very tiny), they are extremely fragile and survive only short periods of time. To help lengthen their short lives, researchers normally create qubits in highly shielded and extremely cold environments (nearly absolute zero). That makes quantum computers very expensive to build and maintain and why Simonite can confidently predict you’ll never be getting one that will fit in your pocket. The number of qubits researchers are working with varies as does the success they are achieving. Andrew Masterson reports a team led by Xiaogang Qiang from the Quantum Engineering Technology Labs at the University of Bristol in the UK was thrilled when it was able to design “a new generation silicon chip that can control two qubits of information simultaneously.”[4] As Masterson notes, “The ultimate goal of quantum information programming [is] a device capable of being reprogrammed to perform any given function.” The reason the new chip is an important breakthrough is because it “overcomes one of the primary obstacles facing the development of quantum computers. Using current technology, operations requiring just a single qubit (a unit of information that is in a superposition of simultaneous ‘0’ and ‘1’) can be carried out with high precision. However, adding a second qubit and thus enabling quantum entanglement, a critical step for quantum computing, escalates problems dramatically.”

Because quantum computers could render current encryption schemes obsolete, there is an international race to develop the first universal, programmable computer. Recently, the National Science Foundation awarded $15 million in grants to seven U.S. universities (Duke University (project lead), University of Chicago, University of Maryland, Tufts University, MIT, University of California, Berkeley, and the University of New Mexico). Security is not the only reason organizations are pursuing quantum computing. Quantum computers can dramatically improve process optimization which is why big companies like Google, IBM, and Microsoft are also spending large sums to develop quantum computers.

Summary

Whether the pursuit of quantum computing is a treasure quest or a fool’s errand remains to be seen. The hope, however, is that researchers will find computing gold. Simonite concludes, “Despite some definite drawbacks, the age of conventional computers has helped make life safer, richer, and more convenient — many of us are never more than five seconds away from a kitten video. The era of quantum computers should have similarly broad reaching, beneficial, and impossible to predict consequences. Bring on the qubits.”

Footnotes
[1] Tom Simonite, “The Wired Guide to Quantum Computing,” Wired, 24 August 2018.
[2] James Norman, “Quantum Computing Will Revolutionize Data Analysis. Maybe Soon,” Seeking Alpha, 14 March 2018.
[3] Alex Hickey, “But what really is a quantum computer?” CIO Dive, 17 August 2018.
[4] Andrew Masterson, “Two-qubit chip draws quantum computing closer,” Cosmos, 21 August 2018.