Google unveils experimental 72-cubit quantum processor

Quantum processor intended to demonstrate impending 'quantum supremacy' over conventional CPUs, according to research scientist Julian Kelly

Google has unveiled details about a new quantum processor, which it believes could be used to create computers that can solve "real-world problems".

At the annual Physical Society meeting in Los Angeles, California the company claimed that the processor forms part of the company's commitment to develop powerful quantum computers that could change the world.

Julian Kelly, a research scientist from the Quantum AI Lab at Google, explained that the firm is exploring "near-term applications using systems that are forward compatible to a large-scale universal error-corrected quantum computer".

But up until now, the company admitted that developing a suitable quantum processor has been challenging.

We chose a device of this size to be able to demonstrate quantum supremacy in the future

"In order for a quantum processor to be able to run algorithms beyond the scope of classical simulations, it requires not only a large number of qubits," said Kelly.

"Crucially, the processor must also have low error rates on readout and logical operations, such as single and two-qubit gates.

The processor, which Google described as a gate-based superconducting system, will act as a "testbed or research into system error rates and scalability of our qubit technology".

It will also be used for quantum simulation, optimisation and machine learning projects.

Kelly said the principle of the device is to "preserve the underlying physics of our previous 9-qubit linear array technology".

He said: "This device uses the same scheme for coupling, control, and readout, but is scaled to a square array of 72 qubits.

The experimental demonstration of a quantum processor outperforming a supercomputer would be a watershed moment for our field

"We chose a device of this size to be able to demonstrate quantum supremacy in the future, investigate first and second order error-correction using the surface code, and to facilitate quantum algorithm development on actual hardware."

Google claimed that quantum processors with even low-power qualities can outperform the most powerful supercomputers for particular applications, paving the way for scientific research.

The researcher added: "We believe the experimental demonstration of a quantum processor outperforming a supercomputer would be a watershed moment for our field, and remains one of our key objectives.

"We are looking to achieve similar performance to the best error rates of the 9-qubit device, but now across all 72 qubits of Bristlecone. We believe Bristlecone would then be a compelling proof-of-principle for building larger scale quantum computers.

"Operating a device such as Bristlecone at low system-error requires harmony between a full stack of technology ranging from software and control electronics to the processor itself.".