Australian scientists bring quantum computing closer to reality

Washington: Australian scientists have made a breakthrough and found distinct solutions that would make super powerful quantum computing a reality.

Two research teams working in the same laboratories at UNSW Australia created two types of quantum bits, or "qubits" - the building blocks for quantum computers - that each process quantum data with an accuracy above 99 percent.

Professor Andrew Dzurak said that for quantum computing to become a reality, they need to operate the bits with very low error rates. Associate Professor Andrea Morello added that they had come up with two parallel pathways for building a quantum computer in silicon, each of which showed this super accuracy.

The team led by Dzurak discovered a way to create an "artificial atom" qubit with a device remarkably similar to the silicon transistors used in consumer electronics, known as MOSFETs. Meanwhile, Morello's team has been pushing the "natural" phosphorus atom qubit to the extremes of performance.

The high-accuracy operations for both natural and artificial atom qubits was achieved by placing each inside a thin layer of specially purified silicon, containing only the silicon-28 isotope. This isotope is perfectly non-magnetic and, unlike those in naturally occurring silicon, does not disturb the quantum bit. The purified silicon was provided through collaboration with Professor Kohei Itoh from Keio University in Japan.

The next step for the researchers is to build pairs of highly accurate quantum bits. Large quantum computers are expected to consist of many thousands or millions of qubits and may integrate both natural and artificial atoms.

Morello's research team also established a world-record "coherence time" for a single quantum bit held in solid state. The longer the coherence time, the easier it becomes to perform long sequences of operations, and therefore more complex calculations.

The team was able to store quantum information in a phosphorus nucleus for more than 30 seconds.

The findings have been published in the journal Nature Nanotechnology.