Researchers from the University of New South Wales (UNSW) in Australia have set new world records as they discovered solutions to challenges that stymy the development of quantum computers. The scientists achieved a breakthrough with the development of the first silicon quantum technologies that have the capacity to hold data with more than 99 percent accuracy.
Andrew Dzurak, from the Centre of Excellence for Quantum Computation & Communication Technology at UNSW's School of Electrical Engineering and Telecommunications, said that a crucial component of making quantum computing a reality is to operate qubits with very low error rates. Also known as quantum bits, qubits are the building blocks of the super powerful quantum computers.
In two separate studies published in the Oct. 12 issue of Nature Nanotechnology, the researchers reported how they have come up with two new types of qubits that can process quantum data with over 99 percent accuracy, a milestone that could eventually lead to the realization of quantum computing.
The first method involves the use of the natural atom of phosphorus. The researchers, led by Andrea Morello of UNSW's Centre of Excellence for Quantum Computation & Communication Technology, tweaked advances they have achieved in an earlier research that used phosphorous atoms as qubits. Using phosphorus atoms in silicon only yielded 50 percent accuracy but the removal of all the silicon 29 isotopes achieved a much better result.
"We solved the problem by removing all the silicon 29 isotopes that have magnetic spin leaving only silicon 28, which has no magnetic spin to influence the phosphorous, giving us an accuracy of 99.99 percent," Dzurak said.
The second approach involves a new method of developing artificial atom qubit with a device known as MOSFET which is similar to the silicon transistors that are found in laptops and smart phones. For both the natural and artificial atom qubits, the high accuracy operation is attained by placing them inside a thin layer of purified silicon that only has the silicon-28 isotope, which is non-magnetic and does not disrupt the quantum bit.
The researchers also achieved a world-record for achieving coherence time of 30 seconds.
"Coherence time is a measure of how long you can preserve quantum information before it's lost," Morello explained adding that half a minute is already comparable to eternity in the quantum world. "We've now come up with two parallel pathways for building a quantum computer in silicon, each of which shows this super accuracy."