‘Hot Qubits’ Report From Australia’s UNSW Sydney Shows Steps Toward Scaling With Silicon

Hot qubits made in Sydney break one of the biggest constraints to practical quantum computers

Excerpts and salient points ~

+  The researchers’ proof-of-concept quantum processor unit cell, on a silicon chip, works at 1.5 Kelvin – 15 times warmer than the main competing chip-based technology being developed by Google, IBM, and others, which uses superconducting qubits. “This is still very cold, but is a temperature that can be achieved using just a few thousand dollars’ worth of refrigeration, rather than the millions of dollars needed to cool chips to 0.1 Kelvin,” explains Dzurak.

Dr Henry Yang and Professor Andrew Dzurak with a dilution refrigerator designed to keep qubits operating at extremely cold temperatures. Picture: UNSW Sydney

“Our new results open a path from experimental devices to affordable quantum computers for real world business and government applications,” says Professor Dzurak. [Pictured:  Dr Henry Yang and Professor Andrew Dzurak with a dilution refrigerator designed to keep qubits operating at extremely cold temperatures. Image Credit: UNSW Sydney]

+  In a paper published in the journal Nature today, Dzurak’s team, together with collaborators in Canada, Finland and Japan, report a proof-of-concept quantum processor unit cell that, unlike most designs being explored worldwide, doesn’t need to operate at temperatures below one-tenth of one Kelvin. Dzurak’s team first announced their experimental results via the academic pre-print archive in February last year.

+  Then, in October 2019, a group in the Netherlands led by a former post-doctoral researcher in Dzurak’s group, Menno Veldhorst, announced a similar result using the same silicon technology developed at UNSW in 2014. The confirmation of this ‘hot qubit’ behaviour by two groups on opposite sides of the world has led to the two papers being published ‘back-to-back’ in the same issue of Nature today.

+  The unit cell developed by Dzurak’s team comprises two qubits confined in a pair of quantum dots embedded in silicon. The result, scaled up, can be manufactured using existing silicon chip factories, and would operate without the need for multi-million-dollar cooling. It would also be easier to integrate with conventional silicon chips, which will be needed to control the quantum processor.

Source:  UNSW Sydney.  Newsroom,  Hot qubits made in Sydney break one of the biggest constraints to practical quantum computers…

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