Quantum Computing Now Exists But Uses Are Limited

Friday - May 19 2023, 16:17 UTC - 1 year ago

Quantum Computing currently exists but is limited in what it can do. Mostly used to experiment and for highly specific calculations, Quantum Computing is connected to existing supercomputer infrastructures worldwide, with the Italian Football League using one during the coronavirus pandemic.

You may be one of those waiting for the quantum computer, the arrival of which we have been told is imminent for several years. Already at this point, DTU Associate Professor Sven Karlsson begins to look a little strained, because among his partners are the two European companies AQT and IQM which produce and sell quantum computers."It's a common misconception that the quantum computer doesn't exist yet. It does already exist, so it's not something we need to wait for. However, the current quantum computers aren't yet all that large, which obviously limits how complicated the calculations can be, but they exist and are being used," says Sven Karlsson.

One example is IBM's quantum computers, which anyone can access via the internet. In addition, there are quantum computers in scientific laboratories, in supercomputer centers, at universities, and so on—worldwide. These are also among the customers to which AQT and IQM sell their products.

--- Mostly for experiments --- .

It has not yet been possible to build quantum computers with many quantum bits. Quantum bits are used to process the information in the computer, and a low number of quantum bits therefore limits the complexity of the calculations the quantum computer can perform. Sven Karlsson therefore characterizes the current use as primarily experimental, making it possible to play with and understand the technology.

"The technical level of the current quantum computers is somewhat similar to the first stage of our current computers. When they first appeared in the 1950s, there were only a limited number of them, and, back then, they couldn't make larger calculations than those any calculator can perform today." .

However, there are examples of calculations performed using a quantum computer. One of the calculations known to Sven Karlsson was done during the coronavirus pandemic. The Italian football league needed to know how best to schedule the matches so that the different football teams came into contact with each other as little as possible to reduce the risk of infection. Likewise, travel distances for the players had to be limited, as travel by air was banned.

"A quantum computer is well suited for calculations of this type that will take too long for an ordinary supercomputer. The quantum computer can examine many solutions simultaneously and is therefore more efficient at such calculations than a supercomputer," says Sven Karlsson.

--- Connects to supercomputers --- .

Sven Karlsson and his colleagues' collaboration with AQT and IQM includes developing the hardware and software needed to connect the quantum computer to supercomputers.

"The future quantum computers will initially largely be connected to the relatively few high-performance computing centers with supercomputers that exist worldwide. The centers have already built an infrastructure with the right competences to operate the quantum computers, and it also makes sense to invest in relation to the existing centers. Today, a quantum computer costs around DKK 150 million, so it's a relatively large investment," says Sven Karlsson.

The quantum computer will not replace supercomputers. Instead, it will supplement them and be used for highly specific calculations. Nor will the quantum computer have its own user interface, but must be accessed via the same access protocols used for supercomptuers.