Scientists produce most stable qubit, largest quantum circuit yet

A pair of breakthroughs sees researchers continue to inch towards a quantum computer.
Written by Chris Duckett, Contributor on

Researchers at the University of Sydney, Australian National University, and the University of Tokyo have brought together the largest number of quantum system in a single component thus far, taking the record from a previous high of 14, to the new record of 10,000.

"The two main obstacles to creating quantum computers are the precise control of tiny quantum systems and the issue of scalability, which is the ability to make bigger and bigger quantum computers out of small parts," said Dr Nicolas Menicucci, a theoretical physicist at the University of Sydney's School of Physics.

"We have made a breakthrough in scalability for the basic 'circuit board' of a quantum computer made out of laser light."

Menicucci created the proposed design, which was built by the research team at the University of Tokyo, and said that the next stage would be injecting precision into the system.

"To take advantage of this breakthrough in scalability, we'll need further breakthroughs in the precise control of these devices. This is the next step," he said.

An article on the research has been published in the journal Nature Photonics today.

Meanwhile, a breakthrough with similar orders of magnitude has been announced by a research team led by physicists at Vancouver's Simon Fraser University.

The team managed to create a quantum bit, or qubit, that was stable at room temperature for 39 minutes, the CBC reports. The qubit was made from having phosphorous atoms embedded in a silicon crystal.

Even though the qubits survived at room temperatures, and survived cooling and reheating processes, the qubits still need to be read at temperatures lower than 10 Kelvin (-263.15 Celsius or -441.67 Fahrenheit), and instead of having multiple qubits, each qubit was created with the same state. The researchers said that allowing multiple qubits with differing states would be the next challenge, and that they hope someone could create a system to read the qubits at room temperature.

The researchers' paper was published in the journal Science.

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