UNSW Sydney-led research paves the way for large silicon-based quantum processors for real-world manufacturing & application

(Phys.org) UNSW Sydney-led research paves the way for large silicon-based quantum processors for real-world manufacturing and application.
Australian researchers have proven that near error-free quantum computing is possible, paving the way to build silicon-based quantum devices compatible with current semiconductor manufacturing technology.
“Our operations were 99 percent error-free,” says Professor Andrea Morello of UNSW, who led the work. “When the errors are so rare, it becomes possible to detect them and correct them when they occur. This shows that it is possible to build quantum computers that have enough scale, and enough power, to handle meaningful computation.”
This piece of research is an important milestone on the journey that will get us there,” Prof. Morello says.
Morello had previously demonstrated that he could preserve quantum information in silicon for 35 seconds, due to the extreme isolation of nuclear spins from their environment.
“In the quantum world, 35 seconds is an eternity,” says Prof. Morello. “To give a comparison, in the famous Google and IBM superconducting quantum computers the lifetime is about a hundred microseconds—nearly a million times shorter.”
But the trade-off was that isolating the qubits made it seemingly impossible for them to interact with each other, as necessary to perform actual computations.
The paper describes how his team overcame this problem by using an electron encompassing two nuclei of phosphorus atoms.
“If you have two nuclei that are connected to the same electron, you can make them do a quantum operation,” says Dr. Mateusz Mądzik, one of the lead experimental authors.
“This really is an unlocking technology,” says Dr. Serwan Asaad, another lead experimental author. “The nuclear spins are the core quantum processor. If you entangle them with the electron, then the electron can then be moved to another place and entangled with other qubit nuclei further afield, opening the way to making large arrays of qubits capable of robust and useful computations.”