Quantum breakthrough massively speeds up the speed of the 'building blocks' of computers of the future

Scientists can now work towards actually creating a working quantum computer

How a large-scale quantum computer might look (Winfried Hensinger)

Researchers have broken speed records for the building blocks of quantum computing, getting them ready to actually build the computers that could revolutionise the world.

Quantum computers could come to dwarf the processing power of today's conventional computers, by harnessing the strange effects of quantum physics. They could eventually allow for new techniques in everything from healthcare to physics, allowing work to be done at a speed almost inconceivable today.

But scientists are still working at the most foundational level of such technology, attempting to put together the building blocks. The new research drastically improves those building blocks: making the "logic gates" that will be used in those computers faster than they've ever been before.

The Oxford researchers are using a trapped-ion technique, where they place two charged atoms in a state of quantum entanglement. Entanglement is the strange phenomenon that Einstein called "spooky", where atoms can have strange effects on each other despite being a long distance apart, and that will be at the heart of quantum technology.

The charged atoms can contain information in the form of quantum bits, or qubits. Those qubits will be the key part of quantum computing if they can be effectively controlled.

The Oxford researchers had already used that technology to create logic gates that were far more precise than any ever created before. And the new research speeds them up, improving it by as much as 60 times.

Now the researchers say they can move on to actually use those breakthroughs in practical ways, putting them into the promised quantum computers.

"Quantum computing will be ideally suited for tasks such as factorising large numbers or simulating complex reactions between molecules to help with drug development," said Vera Schäfer, an Oxford doctoral student who worked on the research.

‘Previous work in our group produced quantum logic gates with record-breaking precision. We then began work on increasing the speed of those gates without compromising their accuracy, which is tricky. Trapped ions move like a pendulum during the gate operation, but when this process is sped up they become sensitive to a number of factors that cause errors.

‘By making use of a technique that precisely shapes the force on the ions such that the gate performance becomes robust to these factors, we were able to increase the speed by a factor of 20 to 60 compared with the previous best gates – 1.6 microseconds long, with 99.8% precision.

‘We have now produced the highest fidelity and the fastest gate, reaching a point where our gates are in principle good enough for quantum computing. The next step is to think about it in practical terms and work towards scaling up our system to create a viable quantum computer.’