A New Startup Intends to Build the World’s First Large-Scale Quantum Computer

An ambitious plan to build a quantum computer the size of a soccer field could soon become a reality. A startup founded by the researchers behind the idea has just come out of stealth with $4.5 m illion in funding.
While there has been some headline-grabbing progress in quantum computing in recent years—not least Google’s announcement that it had achieved quantum supremacy — today’s devices are still a long way from being put to practical use.
The reason quantum computers are so promising is their potential to solve problems beyond the reach of even the most powerful supercomputers. While bits in a conventional computer can only adopt the values of 1 or 0, the qubits at the heart of a quantum computer can adopt multiple combinations of 1 or 0 at the same time thanks to the quantum mechanical phenomena of superposition.
Another quantum phenomena called entanglement makes it possible to link many of these qubits together. The combination means that while a conventional computer would have to chug through the numbers sequentially, an ideal quantum computer could sort through every possible combination of 1s or 0s instantly.
Given their complexity, though, this is only useful for problems so big that it would take a conventional computer a very long time to work through. That requires a lot of qubits, far more than anyone has managed to string together so far. The superconducting qubits that industry leaders like Google, IBM, and D-Wave use are also noisy, so it’s expected that we’d need even more qubits to carry out error-correction as well.
The difficulty of scaling up these devices is the reason why people often talk of decades before we see practical uses for quantum computers. But in 2017 researchers from the University of Sussex in the UK put forward a bold plan for a modular quantum computer that could quickly scale up to billions of qubits. And now a startup founded by the same team, called Universal Quantum , has come out of stealth with plans to commerciali z e the idea.
The company is taking a different tack to the market leaders, building its qubits out of trapped ions—charged atoms confined in a particular spot using using electromagnetic fields—rather than the superconducting circuits that have become the most popular solution in recent years.
Trapped ions are promising because they are all identical and therefore don’t suffer from the tiny variations in fabrication that can impact superconducting circuits. It’s also possible to push them into particular states and read those states back out with high fidelity. And most importantly, they are able to maintain their fragile quantum states for much longer than other approaches, which gives them more time to carry out calculations.
But combining large numbers of t rapped ions in a single device while still maintaining control of them has proven tricky, and circuits made up...