Quantum Computing Is Here But It's Also At Least A Decade Away

By John Oncea, Editor

The arrival of quantum computing is a paradox. On one hand, it’s here. On the other hand, it’s not. Confused? Read on to learn more about when, if at all, quantum computing will take the throne.

We’ve written a lot about quantum technologies this year, from the bright future of quantum sensing to why quantum computing will break your heart to Q-Day. We even touched on quantum receivers last year.

Some of these articles praise quantum’s inevitable ascent to an omnipresent technology, others wonder if it will ever deliver on its promise. Suffice it to say, there’s no consensus as to what’s next.

But even though people have been saying quantum computing is just five years away every five years, the truth is it’s already here. According to the Technical University of Denmark (DTU), quantum computers are being manufactured and used but are just not powerful enough to make the large-scale calculations that are expected to be possible in the future.

“It’s a common misconception that the quantum computer doesn’t exist yet,” DTU Associate Professor Sven Karlsson says. “It does already exist, so it’s not something we need to wait for. However, the current quantum computers aren’t yet all that large, which obviously limits how complicated the calculations can be, but they exist and are being used.”

DTU cites IBM’s quantum computers, which anyone can access via the internet, as one example of tomorrow’s technology in action today. “In addition, there are quantum computers in scientific laboratories, in supercomputer centers, at universities, and so on—worldwide,” writes DTU.

So, the question isn’t, “When will quantum computing arrive?” It’s more, “When will quantum computing be useful?”

What Are Quantum Computers And When Will They Be Useful?

Definitions aside, there are almost as many answers to that question as there are people to ask it of. The best answer might come from this MIT Sloan School of Management article: Quantum, an innovation most can’t define and still don’t properly understand (but) might be the next obscure technology to have a seismic effect on business.

Still, MIT does offer up, “Quantum computing applies the laws of quantum mechanics to simulate and solve complex problems that are too difficult for the current genre of classical computers” as a more concrete definition, one that will work for our purposes.

As to when quantum computers will be useful, well … it’s complicated.

“The current field of quantum computers isn’t quite ready for prime time,” writes MIT Management. “McKinsey has estimated that 5,000 quantum computers will be operational by 2030 but that the hardware and software necessary for handling the most complex problems won’t be available until 2035 or later.”

So, our first best guess for a quantum coronation is 2035 which, if only it were that simple.

Follow The Money

MIT Management points to the research of Neil Thompson and Sukwoong Choi who, in their paper The Quantum Tortoise and the Classical Hare: A Simple Framework for Understanding Which Problems Quantum Computing Will Accelerate (and Which It Will Not), note small to moderate-sized problems will not benefit from quantum computing. Those trying to solve large problems with exponential algorithmic gains and those that need to process very large datasets, however, will derive advantages.

Or, as Thompson puts it, “Quantum computing is not going to be better for everything, just for some things.”

But again, when will that be?

Some are pointing to the moment quantum advantage – the ability of quantum computers to solve problems that are beyond the reach of classical computers – is achieved. But Thompson and Choi posit the arrival of quantum won’t occur when it's more useful, rather it will be when the technology becomes cost-competitive with classical computers.

“Their framework establishes the benchmark of quantum economic advantage, which occurs when a particular problem can be solved more quickly with a quantum computer than with a comparably priced classical computer,” explains MIT Management.

The quantum economic advantage is the overlap between these two conditions:

• Feasibility, meaning whether a quantum computer exists that is sufficiently powerful to solve a particular problem
• Algorithmic advantage, meaning that a quantum computer would be faster at completing a particular task compared with a comparably priced classical computer

MIT Management writes businesses need to consider the speed of the computer versus the route, with Thompson adding, “Think of it like a race in getting from point A to point B, and the algorithm is the route. If the race is short, it might not be worth investing in better route planning. For it to be worth it, it has to be a longer race.”

The key takeaway is that quantum computing may not be the best solution for every business problem. Problems that already have effective algorithms, along with most day-to-day business problems involving small datasets, will continue to be best handled by classical computers.

But the usefulness of quantum is not far off as it continues its development solving the problems it is best suited for – those small enough to be processed on a quantum computer, and large enough to benefit from quantum’s algorithmic advantage. This will occur on a continuum, writes MIT Management, adding, “Given the current state of quantum technology, it will be useful sooner for small-scale problems whose solutions offer smaller benefits and will only later be viable for solving more complex problems that promise larger benefits.