Things you need to know about quantum computers

Things that pop-sci articles don’t often tell you

Dr James Wootton
3 min readMay 10, 2018

1. They are just computers

How often do you think about how Facebook looks at the levels of the transistors? I’m guessing probably never. You wiggle your mouse and stare at your screen, and think little about the magic going on in the hot, noisy box.

http://www.computinghistory.org.uk/det/43063/The-Megaprocessor/

For quantum computers, users will have the same experience. Except the box will be bigger, noisier and contain different magic.

2. Just because they are quantum, doesn’t mean they aren’t for you

Sci-Fi these days often seems little different than Fantasy. The writers just have to swap the word ‘magic’ with ‘quantum’, and ‘spell’ with ‘equation’. Unfortunately, this probably makes it seem like anything quantum is mysterious and arcane, to be used only by Wizards (or people with PhDs, at least).

But do you know what else is full of quantum stuff? Transistors! The computer you are reading this on would not work were it not for all the quantum stuff going on inside. And nevertheless, you sit on the toilet with it and read fanfic.

Have confidence in yourself! You’ll find a way to misuse quantum computers too. Why not get started with the ones IBM have on the cloud?

3. They can do simple things

If you’ve heard about quantum computers, you’ve probably heard that we are building them because they can solve problems too complex for normal computers. And they do it by invoking all kinds of quantum stuff. The takeaway message seems to be: they do complicated things in a complicated way.

But that doesn’t mean they’ll always be working at maximum complexity. They can do simple stuff too. You can write a smiley, or make a game, or use them to decide whether it’s pizza night.

A superposition of emoticons I made while watching Iron Man 2

4. They aren’t almost here

This year, the announcement of a 72 qubit device came with fancy logos, T-shirts, and a party with people dressed in carpets. So this is where we are at in terms of progress: even a device smaller than 100 qubits deserves warrant an invasion of humanoid carpets.

To fulfill the promise of quantum computing in terms of actual applications, we need to increase the qubut count to more than 1 million.

Near-term devices will be great for playing with and doing science with. There will be fancy results, and the companies building the fancy hardware will be rightly proud of them. But quantum computers won’t be challenging normal computers at the job of actually being computers for at least a decade or two.

5. D-Wave aren’t in the race. They are running a race of their own.

There’s a company called D-Wave that basically has a fancy quantum slide rule. It might turn out to be extremely useful at certain tasks (like a slide rule). And it might arguably be a computer (like a slide rule). But it isn’t what we usually call a quantum computer, and D-Wave qubits shouldn’t be directly compared to anyone else’s qubits. So if they say they have zillions of them, it still doesn’t mean that the full promise of quantum computing is around the corner.

Now you know things. If you want more hands-on knowledge of quantum computing, follow me or check out the QISKitters publication here on Medium

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Dr James Wootton

Helping to make quantum computers IBM Research . Occasionally misusing them for fun and/or science. Two Ts and no Es. All nonsense here is my own doing