Quantum computing has a hype problem

The qubit systems we have today are a tremendous scientific achievement, but they are not close to having a quantum computer that can solve a problem that anyone cares about. It is similar to trying to make the best phones of the early 1900s. If you could get 10 billion of them to work together in a seamless manner, you could achieve a lot of miracles. It took 60 years of very difficult engineering to go from the invention of transistors to the smartphone with no new physics involved in the process.

I played a role in the development of the theories for the idea of using far more stable qubits in an approach called topological quantum computing. This approach is being worked on by Microsoft. It turns out that the development of quantum-computing hardware is a huge challenge. It's not clear if extensive quantum error correction or a hybrid between the two will be the winner.

Physicists are smart, and some of them are very good at coming up with substantive-sounding acronyms that stick. The idea that small collections of noisy physical qubits could do something useful and better than a computer has led to the acronym NISQ. I don't know what this object is. How many bits? Why is this a computer? What problems can the machine solve?

Some predicted aspects of quantum dynamics have been observed in a recent laboratory experiment. The experiment was an impressive showcase of electronic control techniques, but it showed no computing advantage over conventional computers, which can easily mimic time crystals with a similar number of virtual qubits. The fundamental physics of time crystals were not revealed. Recent experiments simulating random quantum circuits is a highly specialized task of no commercial value.

It could help physics research in fundamental areas such as quantum dynamics with the use of NISQ. Despite a constant drumbeat of hype, the commercialization potential of quantum computing is not clear. I've seen vague claims about how NISQ could be used. I am not an expert in the field, but I have asked the experts and they are perplexed. Since we don't know how machine learning and artificial intelligence work, I think it's possible that NISQ could do this faster. Maybe, but this is hoping for the best.

There are proposals to use small-scale quantum computers for drug design, which is baffling given that quantum chemistry is a minuscule part of the whole process. There are claims that quantum computers will help finance. There are no technical papers that show that small quantum computers can lead to significant improvement in trading or risk evaluation. Several investment banks are jumping on the quantum-computing bandwagon.

When the first transistor was made in 1947, nobody could have predicted how it would lead to laptops and phones. I am all for hope and am a big believer in quantum computing as a potentially disruptive technology, but to claim that it would start producing millions of dollars of profit for real companies selling services or products in the near future is very puzzling to me. How?

One of the most important developments in physics is quantum computing. We can't expectentanglement andsuperposition to transform technology in the near future. It's weird and counterintuitive, but quantum mechanics doesn't guarantee revenue or profit.

When I thought a quantum computer would be built, I was often asked. It is interesting that I no longer face this question as quantum-computing hype has apparently convinced people that these systems already exist or are just around the corner. Predicting the future of technology is impossible. An analogy with the past could be drawn. It took more than 60 years for the aviation industry to go from the Wright brothers to jumbo jets. The question is where quantum computing development should be placed. Is it related to the Wright brothers in 1903? Around 1940, the first jet planes? Maybe we are still way back in the early 16th century, with Leonardo da Vinci's flying machine? I don't know. Nobody else does.

Sankar Das Sarma is the director of the Condensed Matter Theory Center at the University of Maryland, College Park.