Physicist Robert Raussendorf is at the cusp of an exciting new part of his research, where the ideas he has so far only theorized about are finally culminating in a real-world project. He has been studying how the quantum world can be used for computation, but now he’s about to actually build a quantum computer.
“We want to look at these capabilities and now make a fault-tolerant universal quantum computer out of it,” says Raussendorf, associate professor of physics and astronomy at UBC’s Stewart Blusson Quantum Matter Institute.
“The physical basis is different. So we have instead of classical bits we have qubits, and they just have different properties. In a classical bit you have just two states, zero and one. In the qubit you have these states, too, but then you have things in between. You have a continuous spectrum of states in between one and two.”
As though that isn’t different enough from the way computers work now, as soon as there are multiple qubits, they also interact with each other.
“If you go to multiple qubits it gets even weirder,” adds Raussendorf.
“Then you find the phenomenon of entanglement. Quantum particles, qubits included, can be correlated in very weird ways. These correlations can be used for quantum computation as well. So there is a completely new technology out here.”
So far, powerful real-world examples of quantum computing have been demonstrated only in isolated examples, leaving a lot of open questions about how to create a stable and universal system. Collaborations within UBC and with Simon Fraser University are making the experimental work possible.
“I am having these ideas about how to make a quantum computer robust against decoherence, but what about reality? Why not build it?” asks Raussendorf.
“This is the the first time that it becomes in range for me to be part of such an enterprise where a quantum computer is actually built and I can feed in my ideas and then hope to be close when my theoretical ideas are being realized in the real world.”