"A single phosphorus atom precisely positioned within a silicon crystal could become a building block for a super-fast quantum computer."

Her team was the first to be able to manipulate individual atoms with "exquisite precision".

Using a technique involving a scanning tunnelling microscope, they were able to replace one silicon atom from a group of six with one phosphorus atom, achieving a placement accuracy of better than half a nanometre. "This device is perfect," Professor Simmons, director of the Australian Centre of Excellence for Quantum Computation and Communication Technology, said.

The single atom sits between two pairs of electrodes, one about 20 nanometres apart, the other about 100 nanometres apart.

When voltages were applied across the electrodes, the nano device worked like a transistor, a device that can amplify and switch electronic signals.