Complete design of a silicon quantum computer chip unveiled

A reimagining of today's computer chips by Australian and Dutch engineers shows how a quantum computer can be manufactured -- using mostly standard silicon technology.

Complete design of a silicon quantum computer chip unveiled
Artist's impression of UNSW's complete silicon quantum computer chip in operation. Credit: Tony Melov/UNSW

UNSW scientists have recently designed a working silicon quantum computer chip that can integrate quantum interactions. The architecture of the chip allows quantum calculations to be performed using existing semiconductor components, known as CMOS.

Andrew Dzurak, director of the Australian National Fabrication Facility at UNSW said, “We often think of landing on the Moon as humanity’s greatest technological marvel. But creating a microprocessor chip with a billion operating devices integrated together to work like a symphony – that you can carry in your pocket! – is an astounding technical achievement, and one that’s revolutionized modern life.”

“With quantum computing, we are nearly another mechanical jump that could be as profound and transformative. However, an entire building configuration to understand this on a solitary chip has been subtle. I think what we have created at UNSW now makes that conceivable. What’s more, in particular, it can be made in an advanced semiconductor producing plant.”

The chip is designed in such way that it can chart a conceivable engineering pathway toward creating millions of quantum bits, or qubits.

Most of the computer chips that are in use today, can’t harness the quantum effects that are essential to solving complex problems. In order to address such major worldwide difficulties – like environmental change or complex disease – it’s, for the most part, acknowledged we will require a large number of qubits working couple. For that purpose, we should pack qubits together and coordinate them, as we do with present-day microchip chips. That is the thing that this new outline expects to accomplish.

Menno Veldhorst, lead author of the paper said, “Our design incorporates conventional silicon transistor switches to ‘turn on’ operations between qubits in a vast two-dimensional array, using a grid-based ‘word’ and ‘bit’ select protocol similar to that used to select bits in a conventional computer memory chip.”

“By selecting electrodes above a qubit, we can control a qubit’s spin, which stores the quantum binary code of a 0 or 1. And by selecting electrodes between the qubits, two-qubit logic interactions, or calculations, can be performed between qubits.”

A quantum PC exponentially extends the vocabulary of double code utilized as a part of present-day PCs by utilizing two spooky standards of quantum material science – specifically, ‘ensnarement’ and ‘superposition’. Qubits can store a 0, a 1, or a discretionary blend of 0 and 1 in the meantime. What’s more, similarly as a quantum PC can store numerous esteems without a moment’s delay, so it can process them at the same time, doing different operations on the double.

Complete design of a silicon quantum computer chip unveiled
Silicon quantum computer chip from below, showing the qubits interacting with the CMOS architecture above. Credit: Tony Melov/UNSW

This would enable an all-inclusive quantum PC to be a large number of times speedier than any regular PC when tackling a scope of vital issues.

Yet, to take care of complex issues, a valuable all inclusive quantum PC will require countless, potentially millions, since a wide range of qubits we know are delicate, and even small blunders can be immediately increased into wrong answers.

Dzurak said, “Our chip blueprint incorporates a new type of error-correcting code designed specifically for spin qubits, and involves a sophisticated protocol of operations across the millions of qubits. It’s the first attempt to integrate into a single chip all of the conventional silicon circuitry needed to control and read the millions of qubits needed for quantum computing.”

This new chip actually relies on its silicon spin qubit approach – which already mimics much of the solid-state devices in silicon that is the heart of the US$380 billion global semiconductor industry – it shows how to dovetail spin qubit error correcting code into existing chip designs, enabling true universal quantum computation.

Dzurak said, “It’s kind of swept under the carpet a bit, but for large-scale quantum computing, we are going to need millions of qubits. Here, we show a way that spin qubits can be scaled up massively. And that’s the key.”