Physicists at the University of New South Wales are leading the race to build computers exponentially faster than any we currently use, according to an assessment published by the scientific journals group, Nature.
The assessment follows a series of four papers in this year’s Nature journals, which show the team has achieved some key steps in creating quantum computers: accurately holding and processing quantum information in one qubit; passing information between two qubits; and optimising processing efficiency.
Researchers at the UNSW node of the ARC Centre of Excellence for Quantum Computation and Communication Technology have achieved these steps using silicon, which is the base material currently used to build computers. Not only is it inexpensive and abundant, but there is already a trillion-dollar global industry geared to handling and manipulating silicon.
Quantum computers will use the spin, or magnetic orientation, of individual electrons or atomic nuclei to represent data in their calculations. Two of the papers demonstrate that either phosphorus donor atoms or quantum dots within silicon can hold and process quantum information with more than 99 per cent accuracy.
Another paper shows that the phosphorus donor atoms within silicon have the capacity to link up and pass spin-encoded information between them. And the fourth paper outlines a method that can be used to determine where best to place the donor atoms within silicon crystals for maximum data processing efficiency.
Previously physicists from the same groups have shown it is possible to place individual atoms in silicon and to change the spin state of an individual phosphorus donor atom in a silicon crystal and to measure that change—in other words to write and read information in a quantum state, respectively.