Quantum computers real-and at the same time not real
We’ve heard a lot about quantum computers in recent years, and a lot of it is just wrong. Wrong enough for quantum physicist Scott Aaronson to put his name to a comic strip that should shame us all into being a bit more precise about it.
In the first weeks of 2017, had D-Wave, the only commercial quantum computing company, launched a 2000 qubit (quantum bit) system and announced one of the new machines is pre-sold to a security company. We also heard that a team including scientists from Google and multiple universities has created a blueprint for a large scale quantum computer system.
In our simplified world, we’re often told that quantum computers are really powerful because they can process multiple inputs at once. It’s thanks to quantum superposition, where multiple states of a quantum system can be said to exist at the same time. It’s not as simple as that, as Aaronson’s comic (created with Zach Weinersmith) makes clear.
Essentially, quantum computers are systems designed to solve a particular problem, whose qubits will eventually settle on the best solution. Wrong answers cancel out and the right answer emerges.
So it’s not as exciting as reports may say. But the two announcements, if you like, do illustrate the two kinds of quantum computer that exist in today’s real world. It’s not a quantum superposition, but it’s definitely two alternative views. There’s D-Wave, keen to sell machines now, and there are academics, who want their names on solid science.
The system is under the influence of strong external forces. Whether or not quantum computers exist, there are strong demands that they should, as well as fears of what they might do.
A quantum computer, it is said, could enable the decryption of codes which are currently uncrackable. Anyone with such a machine could access any site and read any message.
Just the suggestion that something like that might exist is enough to ensure a huge effort to build one - and to build defenses against it.
As MIT Technology Review puts it, paranoia about quantum computing is creating a whole new industry. The US National Institute of Science and Technology (NIST) wants government agencies to be able to switch on “post-quantum” encryption by 2025.
But till we know what quantum computers can do, how can we possibly prepare against them? It’s not at all clear if we can and some serious researchers like Bruce Schneier, suggest we have to wait and see.
The implications for data centers are also unknown. If quantum computers are that much more powerful, will we use fewer machines and consume less power? On past experience of earlier tech revolutions, I’d say that’s not very likely.
Like the rest of the world, the data center community has to watch the box, wait for it to open, and see if Schrodinger’s cat is a live wire or a dead duck.
Image by: dwavesys.com