SYDNEY, Sept. 27 (Xinhua) -- Australian engineers have announced a breakthrough in quantum computing, unveiling the first working quantum bit in silicon.
Sydney-based researchers have been able to read and write data using the spin of an electron, bound to a single phosphorous atom, a significant step forward in the era of ultra-powerful computer engineering. Embedded in a silicon chip, this device will form the basic unit of data for quantum computing.
Quantum bits have been created in diamond before, but never in silicon, which allows the electron spin to retain information for longer before it is scrambled and lost.
Silicon is also used in modern computer chips, and may transfer more easily to the manufacturing industry.
"This really is the key breakthrough in realising a silicon quantum computer based on single atoms," said Andrew Dzurak, a nanoelectronics professor at the University of NSW in Sydney, who was involved in the study, along with researchers from Melbourne and London.
The supercomputers of the future, quantum computers promise to solve complex problems at rapid speeds far beyond the abilities of today's technology.
Their potential to quickly search large databases, crack modern encryption codes, and design new types of targeted pharmaceuticals with atomic models could be extremely useful for finance and healthcare industries, and for government, security and defence organisations.
However, the difficulties of controlling single atoms and electrons means that full-scale working quantum computers are still a long way off.
"I would say it will be at least a decade before a demonstrator system is built .. and even longer, maybe twenty years, before commercial products are available," said Dzurak. " There are many engineering steps beyond this to build a full-scale quantum computer."
Previously, the researchers had discovered how to read the state of an electron's spin. Now, writing the spin state completes the operation of the quantum bit, or 'qubit'.
"We can 'write' whatever state we wish to our qubit," said Dzurak. "We are using a microwave field to control just one electron spin .. to encode a 'bit' of information that can be used for computing at the single atom level."
The next step for the engineers will be to link two qubits together to create a more complex system the basic processing unit of a quantum computer.
"We will put two atoms so close together that the electrons bound to them start to 'overlap', share some of the space they occupy," said Associate Professor Andrea Morello, a quantum physicist and electrical engineer also from UNSW. "This results in a magnetic interaction between them, that you can control and use for computer operations."
In current computing, 'bits' convey information by representing either a zero or a one like a switch being on or off. The quantum computing equivalent is the direction of the electrons' spin a clockwise spin can represent a '1', anticlockwise a '0'.
But quantum particles can exist in two or more states at once, and many linked qubits can increase the computer's power exponentially. Two qubits can increase the possible operations by four, three qubits by eight, etc.
"With just 300 physical qubits the amount of information stored is roughly equivalent to the total number of atoms in the universe," said Morello.
The ability to try out trillions of different solutions at the same time will make quantum computers consummate problem-solvers, and perhaps open the door for new applications human cannot yet comprehend.