World first as two quantum computers go head to head

Scientists recently published the world's first open source blueprint for a quantum computing device, and sure enough, no sooner than the designs go public we see two cage fighters come out of the shadows and decide that it's time for a smackdown to prove who's the biggest brawler in town. In the red trunks, weighing in with just five qubits, a quantum computer from the University of Maryland in College Park, and in the blue trunks, also with five qubits, its rival from IBM.

Welcome to the first apples for apples quantum computer fight off.

Researchers have described a series of experiments that, for the first time, saw two quantum computing devices, built using different underlying technologies, run the same "split decision" algorithms to establish which would win. The qubits, which are the quantum equivalent of binary bits, in IBM’s chip are made from superconducting metals, while the University of Maryland’s uses electromagnetic fields to trap ytterbium ions.

The experiment was made possible because the two chips, while using different underlying physics, both run algorithms in the same way. And because IBM has opened its chip up, allowing it to be programmed online by researchers, the University of Maryland team was able to give it the same challenge as its own device.

Ultimately, the IBM device was faster, but, crucially, it was also less reliable – something that a few recent quantum computing breakthroughs might be able to help with. But for now at least that was because the University of Maryland device uses qubits that are all interconnected, which means they can all share information with each other. IBM’s, meanwhile, must swap information via a central hub, and that process can cause delicate quantum states to be destroyed.

The chips are still modest in power, and the results don't yet prove that one of the two technologies will win out. But the ability to directly compare their abilities will become even more useful in the future, as researchers seek to whittle down a broad field of competing quantum approaches to find the best.

In the past, quantum computers, such as DWave’s contentious system, have been pitted against regular computing systems rather than their quantum rivals, something that last year helped to demonstrate – again contentiously – that quantum computers were able to operate a hundred million times faster than their traditional siblings.

As Science notes, the results of the new test are perhaps less exciting than their symbolic nature. In the past, it’s not been possible to directly compare the performance of quantum devices in this way. The fact it can now be done is another sign that quantum computing nudges ever closer to reality.