Quantum computer components: Learn the basics

Quantum computers look nothing like regular computers. Here is a primer on what the parts are inside a quantum computer, with insights from an expert at IBM.

If quantum computing is the future, then info-tech staffers will need to learn about new kinds of components.

Most pictures of quantum computers show what's become known as a steampunk chandelier, with several tiers of golden vertical rods, metal cables running everywhere, but nothing at all resembling a computer. What is all that stuff, and how does it compare to what's in a traditional server?

SEE: IT leader's guide to the future of quantum computing (Tech Pro Research)

The actual processor, which researchers call the payload, is in a microchip-like package about 1 inch by three-quarters of an inch. That's at the bottom of the assembly in a part called the cryostat—its name was selected because it needs to be cold and stable.

As for the shiny Rube Goldberg contraption above it: "All of that is in support of the chip itself," explained IBM's Bob Sutor, the vice president in charge of quantum computing strategy. Most of the rods are gold-plated brass that moves cooling fluids, because gold reflects away heat in the form of infrared radiation, he explained. And most of the cables contain microwave signals, which send low-energy pulses that command or read data from each qubit, depending on the shape of the wave. Finally, the whole assembly is nearly vacuum sealed.

SEE: Quantum computing: An insider's guide (TechRepublic download)

Sutor emphasized the importance of keeping the payload cold. Balmy room temperature of 72 degree Fahrenheit is 295.372 degrees Kelvin. Outer space is about 2.7 degrees Kelvin, and yet quantum chips need to be kept at just .01 degrees above absolute zero. (There goes the notion of warming up your data center.)

The programming is performed on a normal computer, which has an interface to those microwave signal generators and readers. Coding there is not unlike assembly language, where you're directly interacting with a processor and playing traffic cop for which information goes where. But forget the notion of quantum memory or storage. "Today there is no notion of on-the-side quantum storage. When will we have quantum RAM? This is going to be related to fault tolerance, qubits that will hold their value long enough," which is probably a decade from now, Sutor said.

So these systems are strictly volatile for now. Qubits are hard enough for today's scientists to keep stable when the computers are turned on, let alone when they're off.

Right now, IBM's biggest system has 50 qubits. In the future, "Let's say you get to 300. The number of pieces of data a quantum computer can access is more than the number of atoms in the observable universe," Sutor said.

Big Blue highlighted its latest design at the Consumer Electronics Show this month, which seems like an odd choice considering there is nothing consumer-oriented about quantum computing. They put the computer inside a dark chassis, just like an IBM mainframe, with an 81-square-feet footprint. The official announcement cites it as the "world's first integrated quantum computing system for commercial use," but that implies much that doesn't exist—"for commercial use" is the company's goal, but barely at all what is possible today.

SEE: CES 2019: Did IBM just reveal first commercial quantum computer? (ZDNet)

Currently, you can write simple programs and interact with a system that lives in an IBM laboratory. The company is secretive about how many such computers it's built: There are a few in one lab, a few in another, and so on. It's likely the total number is less than a dozen or two. Each one is a custom improvement over the previous one, and IBM fabricates each chip itself. "We are not at the point of having an assembly line," Sutor said.

At this rate, is our first sentence true—is quantum computing the future? "These are not backroom science experiments," Sutor asserted, with a caveat: "The world is a hybrid. It will continue to be a hybrid for decades if not centuries."

Computer security is among the first real applications. Qubits are better at making randomness than any conventional computer on Earth, and random numbers are essential for encryption. In theory, by the time a hacker determined the key to your lock, the lock would have changed. "Unhackable" is a dangerous term, but quantum random number generators could be much closer than anything current, and these are already real products you can buy.

Also see


IBM's Q System One quantum computer

Image: IBM

About Evan Koblentz

Evan became a technology reporter during the dot-com boom of the late 1990s. He published a book, "Abacus to smartphone: The evolution of mobile and portable computers" in 2015 and is executive director of Vintage Computer Federation, a 501(c)3 non-p...

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