Andrew Dzurak and his team have built a quantum logic gate in silicon for the first time.
An Australian team of engineers has built a quantum logic gate in silicon for the first time, making calculations between two qubits of information possible – and thereby clearing the final hurdle to making silicon quantum computers a reality. Their work was published online in the international scientific journal, Nature, on 5 October 2015 (London time).
It's the first time calculations between silicon quantum bits has been demonstrated. To achieve this, the University of New South Wales (UNSW) team constructed a device, known as a 'quantum logic gate', that allows calculations to be performed between two quantum bits, or 'qubits'. The advance completes the physical components needed to realise super powerful silicon quantum computers.
Any conceivable application, or software program, that would run on a quantum computer is made up of a series of basic one-qubit and two-qubit calculations.
Until now it had not been possible to make two silicon quantum bits "talk" to each other, to perform such "two-qubit" calculations, or "logic gates". The UNSW result means that all of the physical building locks have now been constructed, and so computer engineers can finally begin the task of building a functioning quantum computer in silicon.
Industrial manufacture now possible
A key advantage of the UNSW approach is that they have reconfigured the 'transistors' that are used to define the bits in existing silicon chips, and turned them in qubits.
"Because we use essentially the same device technology as existing computer chips, we believe it will be much easier to manufacture a full-scale processor chip than for any of the leading designs, which rely on more exotic technologies," says Professor Dzurak.
"This makes the building of a quantum computer much more feasible, since it is based on the same manufacturing technology as today's computer industry," he adds.
Dzurak noted that that the team had recently "patented a design for a full-scale quantum computer chip that would allow for millions of our qubits, all doing the types of calculations that we've just experimentally demonstrated."
He said that a key next step for the project is to identify the right industry partners to work with to manufacture the full-scale quantum processor chip.