Build it and they will come – chip design creates computer blueprint

The design of a 3D silicon chip architecture clears another hurdle in the international race to build quantum computers. Researchers at the University of Melbourne and the University of New South Wales (UNSW) have designed a chip based on single atom quantum bits, creating a blueprint for building a large-scale silicon quantum computer. “Our Australian team has developed the world’s best qubits in silicon. However, to scale up to a fully operational quantum computer we need more than just many of these qubits – we need to be able to control and arrange them in such a way that we can correct errors quantum mechanically,” says Professor Lloyd Hollenberg, the Deputy Director of the CQC2T, who led the work with Dr Charles Hill. “In our work, we’ve developed a blueprint to build a full-scale quantum computer, which is unique to our system of silicon qubits,” Lloyd says. The theoretical modelling team has worked closely with the experimental teams at UNSW to design a two-dimensional array, which is positioned on a plane that is far more tolerant to errors. This layer is sandwiched between two layers of wires in a three-dimensional architecture. The unique technologies developed at UNSW for single atom placement and 3D patterning (Professor Michelle Simmons’ team) and accurate control of the atom’s charge (Professor Sven Rogge’s team) have made this novel architecture feasible. By applying voltages to a sub-set of these wires, multiple qubits can be controlled in parallel, a series of operations can be performed with far fewer controls, and errors can be corrected more quickly. This development provides a blue-print to realise a full-scale, error corrected quantum computer. Banner image: Lloyd (right) and Charles (left) have developed a blueprint to build a full-scale quantum computer. Credit: Casamento Photography