Cryogenic chips could solve quantum computer scaling problems

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Researchers and engineers from QuTech and Intel jointly designed and tested a cryogenic chip, which promises to offer the solution to tackle the ‘wiring bottleneck’ hampering the realization of a fully integrated and scalable quantum computer.

The findings were published in Nature, the scientific journal. Each basic unit of the quantum computer is called a qubit and is catered to by one wire.

For a scalable quantum computer, you’d have to deal with millions of qubits and for that, you will need a million wires, as lead investigator Lieven Vandersypen explains.

The wiring bottleneck

This problem is that the millions of wires are not feasible as a solution. Traditional computers, like the ones we use now, have modern processors with billions of transistors and a few thousand connections. The wiring problem becomes worse in quantum computers, given the cryogenic temperatures required to operate qubits.

Qubits hover at around 10 millikelvin or -273 degrees Celsius, while the electronics that control them operate at room temperature.

The new chip was tested and designed to solve that problem and has been named Horse Ridge, after the coldest place in Oregon, where the Intel lab is found.

What the Horse Ridge team did

Edoardo Charbon, the co-lead investigator said that the team used the same technology leveraged for the conventional microprocessors (CMOS technology). For their chip, the team used the Intel 22nm low-power FinFET technology.

They also used special techniques to ensure the chip would be operational and able to direct qubits with a high degree of accuracy. The controller chip and qubits can be integrated into the same package (they are all made using silicon), to further alleviate the bottleneck.

The quality and programmability details of the chip are impressive and deserve further reading. Access the paper here.