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.
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.
“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.
According to team leader, Andrea Morello, the development is as important for the field as the seminal 1998 paper in Nature by Bruce Kane, which kicked off the silicon quantum computing movement.
The qubit’s value is then determined by combinations of a binary property called spin – if the spin is ‘up’ for an electron while ‘down’ for the nucleus, the qubit represents an overall value of 1.
What this new flip-flop qubit means is a balance that could make future quantum computers small and potentially affordable.