Sun. Feb 5th, 2023

IBM will build and sell commercial 50-qubit universal quantum computers, dubbed IBM Q, “in the next few years.” No word yet on pricing, but I wouldn’t expect much change from $15 million — the cost of a non-universal D-Wave quantum computer.

In other news, IBM has also opened an API (sample code available on Github) that gives developers easier access to the five-qubit quantum computer currently connected to the IBM cloud. IBM will release a full SDK later in the year, further simplifying the process of building quantum software.

You can’t actually do many useful calculations with five qubits, but luckily IBM has news there too: the company’s quantum simulator can now simulate up to 20 qubits. The idea is that developers should now start thinking about possible 20-qubit quantum scenarios so that they are ready to deploy when IBM builds the actual hardware.

Speaking of hardware, it seems that IBM has accelerated its universal quantum computing roadmap somewhat. In May last year, IBM said it would like to build a 50-qubit computer “within the next decade.” Now we have arrived at ‘the coming years’.

IBM has also fleshed out its roadmap for quantum computing a bit and provides some guidance on how it’s actually going to build a universal 50-qubit computer:

IBM’s roadmap for scaling up to practical quantum computers is based on a holistic approach to advancing all parts of the system. IBM will leverage its deep expertise in superconducting qubits, complex high-performance systems integration and scalable nanofabrication processes from the semiconductor industry to help advance quantum mechanical capabilities.

However, despite the aggressive roadmap, there is no evidence that scaling has actually taken place. Consider the original publication, which covered nine computational qubits and a total of 1000 qubits. Now IBM wants their quantum computers to be fully interconnected, so 50 computational qubits require 1,225 connections. Each link seems to need 48 qubits for checking, so 58,800 qubits. This is quite a jump for 1000 qubits on a board.

Compared to D-Wave, which also produces boards with about 1000 qubits, they always have one or two non-functional qubits. In this case, it is very likely that a non-functional qubit is in the connection between two computational qubits, rendering not one, but two nodes useless.

We’ll be much more confident in IBM’s scaling up when we see real documents with an increasing number of computational qubits.

Apart from D-Wave, IBM doesn’t have much competition in quantum computing – and as we’ve explained in the past, both companies seem to be taking a very different approach to quantum computing. IBM has set its sights on building a true universal quantum computer, which can be used to solve any quantum algorithm under the sun. D-Wave seems more focused on scaling up the number of qubits and making sure the system integrates easily with classical computers, but not making sure the qubits are actually qubits.

Me, young and amazed next to a dilution cooling unit.
Enlarge / Me, young and amazed next to a dilution cooling unit.

Sebastian Anthony

While exact pricing, availability, and specs are still a long way off, it’s pretty safe to assume that IBM’s quantum computers will be around the same price as a D-Wave (~$15 million) or perhaps slightly more expensive. Both systems are essentially the same: a fancy chip in a box that contains a multi-stage dilution refrigerator from a company like BlueFors.

Dilution refrigerators take about 24 hours to cool down, but they can then hold the chip at near absolute zero (~5 mK, -273.145 °C) indefinitely, a requirement for today’s quantum computing chips.

And finally, a random tidbit: In the photo to the right, I’m standing on a ladder next to one of IBM’s dilution refrigerators at IBM Research’s headquarters in upstate New York in 2013.

Additional reporting by Chris Lee

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List image by IBM

By akfire1

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