And, showing confidence in its work, the University of New South Wales (UNSW) team has struck a A$83million deal involving Telstra, Commonwealth Bank and the Australian and New South Wales governments to develop, by 2022, a 10 qubit prototype silicon quantum chip.
Andrew Dzurak, director of the Australian National Fabrication Facility at UNSW, said: “With quantum computing, we are on the verge of another technological leap, but a complete engineering design to realise this on a single chip has been elusive. I think what we have developed at UNSW now makes that possible. And, most importantly, it can be made in a modern semiconductor manufacturing plant.”
Fellow researcher Dr Menno Veldhorst said the power of the new design is that, for the first time, it charts a conceivable engineering pathway toward creating millions of qubits.
“To solve problems that address major global challenges, it’s generally accepted we will need millions of qubits working in tandem. To do that, we will need to pack qubits together and integrate them, like we do with modern microprocessors. That’s what this new design aims to achieve.
“Our design incorporates conventional silicon transistor switches to ‘turn on’ operations between qubits in a vast 2D array using a grid-based ‘word’ and ‘bit’ select protocol similar to that used in a conventional memory.
“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.”
But to solve complex problems, a useful universal quantum computer will need a large number of qubits, possibly millions, because all types of qubits we know are fragile, and even tiny errors can be quickly amplified into wrong answers.
Dzurak noted: “Our chip blueprint incorporates a new type of error-correcting code designed specifically for spin qubits, and involving 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.”