An entirely new type of quantum computing has just been invented
Australian researchers have designed a new type of qubit – the building block of quantum computers – that they say will finally make it possible to manufacture a true, large-scale quantum computer. Broadly speaking, there are currently a number of ways to make a quantum computer. Some take up less space, but tend to be incredibly complex. Others are simpler, but if you want it to scale up you’re going to need to knock down a few walls. Some tried and true ways to capture a qubit are to use standard atom-taming technology such as ion traps and optical tweezers that can hold onto particles long enough for their quantum states to be analysed. Others use circuits made of superconducting materials to detect quantum superpositions within the insanely slippery electrical currents.
The advantage of these kinds of systems is their basis in existing techniques and equipment, making them relatively affordable and easy to put together. The cost is space – the technology might do for a relatively small number of qubits, but when you’re looking at hundreds or thousands of them linked into a computer, the scale quickly becomes unfeasible. Thanks to coding information in both the nucleus and electron of an atom, the new silicon qubit, which is being called a ‘flip-flop qubit’, can be controlled by electric signals, instead of magnetic ones. That means it can maintain quantum entanglement across a larger distance than ever before, making it cheaper and easier to build into a scalable computer. “If they’re too close, or too far apart, the ‘entanglement’ between quantum bits – which is what makes quantum computers so special – doesn’t occur,” says the researcher who came up with the new qubit, Guilherme Tosi, from the University of New South Wales in Australia.
The flip-flop qubit will sit in the sweet spot between those two extremes, offering true quantum entanglement across a distance of hundreds of nanometres. In other words, this might be just what we’ve been waiting for to make silicon-based quantum computers scalable.
