Schrödinger's apples and oranges
Do you know what processor is in your smartphone or laptop? I doubt you do. Do you know at what speed your desktop runs your Excel spreadsheet? Not fast enough.
The days when we were remotely aware of the technology under the cover of our computers are gone. And if you knew, it was probably because of the marketing campaign 'Intel inside.’ That’s when Intel, the chip manufacturer, was promoting its Pentium processor. Those were the days when every increase in anything was making headlines.
Naturally, the tech writers were clamouring to write article after article comparing ever-more-impressive speed and size and capabilities of computer technology. A lot of that excitement has faded over time… but a sliver of it is coming back, thanks to quantum computers.
Recent news is revealing a quantum leap in interest:
June 2020. Honeywell says it's got the fastest quantum computer on the planet.
February 2021. A quantum computer just solved a decades-old problem three million times faster than a classical computer.
Oct, 2021. China says it has a quantum computer a million times more powerful than Google’s.
The headlines would lead you to believe that A) quantum computers are production ready, B) quantum computers will replace 'classical' computers shortly and C) quantum computers are faster.
As with all headlines, the truth is somewhat different.
Quantum computers are still a lab and research thing. Even the case studiescoming from D-Wave, the most advanced quantum computer commercially available today, show that the practical side of quantum computers is years away.
Quantum computers are (or will be) good only for solving a small subset of computational problems. Your email client or MS Word won't be running on a quantum computer.
Quantum computers will be good at optimization tasks, computational protein design in drug development, financial modeling, traffic optimization and cybersecurity, etc. In other words, solving very specific problems.
It is also inaccurate to say that a quantum computer is faster than a classical computer. The correct way to put this is that a 'Quantum Computer can solve certain tasks faster than a classical computer as of today.'
It should be also noted that a classical computer provides a definitive answer, like 2+2=4. A quantum computer will tell you that (and I am hugely oversimplifying here) 2+2 = with a 96% probability close to 4.
Let’s take a look back at the news items we saw above, there are some big claims in those stories which deserve a rebuttal. I’ll let IBM do the talking here about quantum supremacy:
'The concept of “quantum supremacy” showcases the resources unique to quantum computers, such as direct access to entanglement and superposition. However, classical computers have resources of their own such as a hierarchy of memories and high-precision computations in hardware, various software assets, and a vast knowledge base of algorithms, and it is important to leverage all such capabilities when comparing quantum to classical.'
When you define the problem in a very, very narrow way, you might come up with an answer which supports your claim. Yes, of course, quantum computing is improving rapidly. There’s no question about it. However, let’s not forget that the world of algorithms and supercomputers is evolving as fast as quantum computers.
Saying which computer is faster is like comparing your Schwartz with Lone Star's. Even trying to measure Quantum Volume as defined by IBM is open to apples-to-oranges comparisons.
Then you have the propaganda that "Zuchongzhi 2.1," is 10 million times faster than the current fastest supercomputer and its calculation complexity is more than 1 million times higher than Google's Sycamore processor. It's the first time that China has reached quantum advantage in a superconducting quantum computing system."
After reading the full article you'd see that it is a theoretical calculation based on lab results. It’s far from any practical use.
Will a quantum computer help you with your next project? Probably not yet. There is still lots of work which all the vendors have to put in to make it practical.
On the other hand, if you are a CIO/CTO and searching for technologies which in 5 years can provide your company with a competitive edge, then quantum computers are reasonable for you to consider. It’s probably too early to implement, but definitely not too early to start planning, so you can get the edge on your competition.
For forward-thinking companies, that will become a recurrent quantum pattern.