Researchers are still trying to figure out all the ways that we can exploit quantum computing. Everything that is possible using a classical bit — the smallest unit of information on classical computers — is possible with a quantum bit or qubit, but qubits can do even more.
“This is the difference we are trying to exploit,” says Robert Raussendorf, associate professor of physics and astronomy at the University of British Columbia, and researcher at the Stewart Blusson Quantum Matter Institute.
The thing that sets quantum physics apart from classical physics is entanglement, says Raussendorf. He describes it as the universal currency of quantum mechanics.
“Let’s look at what’s called a Bell state,” says Raussendorf. “This is the entangled state of two qubits, and they could be spatially separated. One of the qubits could be on the Earth, the other could be on the moon, and they are very strangely correlated.”
Once entangled, no matter how far apart the qubits are, the information they hold is related.
“I could, for example, measure my qubit on Earth, and once I did my measurement over here, I would know in an instant what the state of the qubit at the moon was,” adds Raussendorf. “So we have these very funny correlations that are implied by entanglement, and that’s the physical ramification of it.”
