Scientists have taken a significant step toward creating a revolutionary, fully-functional quantum computer, according to the results of a new study published in the journal Nature Communications on Wednesday.
The researchers from the University of New South Wales (UNSW) in Australia said they had managed to get the most basic units of the next-generation computer, known as quantum bit or qubits, to communicate with each other—an important milestone for the technology and a world first that, until now, had been never been demonstrated.
The reason for the discovery’s significance is that the scientists are now closer to being able to "entangle" their qubits—an essential step to building a viable quantum computer.
Quantum entanglement is a mind-boggling physical phenomenon described by the bizarre laws of quantum mechanics in which pairs or groups of tiny particles interact with each other in such a way that they can no longer be described independently, even if they are separated by vast distances—such as being on opposite sides of the universe, for example.
Once researchers are able to effectively entangle qubits, they will be able to unlock the full potential of quantum computers. A single quantum chip containing just 50 to 60 entangled qubits, for example, would have more power than the world’s fastest supercomputers, which take up whole buildings.
And by the time you get to around the 300 entangled qubits mark, in principle, you would have enough computing power to perform more calculations in an instant than there are atoms in the visible universe. This is possible because the power of qubits scales up exponentially—a property that distinguishes quantum computers from classical computers.
Qubits are analogous to bits in traditional computers, which can exist only in one of two states—0 or 1. Qubits, on the other hand, can exist in states of 0, 1 and everything in between simultaneously. This enables each qubit to perform multiple calculations at the same time, unlike bits in normal computers, which can only handle one at a time.
In light of its latest findings, the UNSW team is leading the world in the race to build the first scalable, silicon-based quantum computer—in which the qubits are made from a single phosphorus atom embedded in a silicon chip.
To date, quantum computers have been notoriously difficult to build and the technology still in its infancy. A small handful of “basic” examples exist; however, they are not ready for widespread personal or commercial use as they mostly require specialized lab conditions to operate.
Despite this, large-scale quantum computers—should they ever be built—would theoretically be able to solve certain problems that even the most powerful classical computers struggle to calculate, revolutionizing fields ranging from machine-learning to medicine and climate science, among many others.