Quantum correction coming
Print
Two quantum information theorists at the University of Sydney have solved a decades-old problem that will free up quantum computing power.
University of Sydney quantum researchers Dominic Williamson and Nouédyn Baspin have come up with a new architecture for managing errors that emerge in the operation of quantum computers.
Their innovative theoretical approach promises to not only enhance the reliability of quantum information storage but also significantly reduce the physical computing resources needed to create ‘logical qubits’ (or ‘quantum switches’ that can perform useful calculations).
This should lead to the development of a more compact ‘quantum hard drive’.
Their theoretical architecture is a three-dimensional structure that allows for quantum error correction across two-dimensions.
Current error correction architecture, also constructed within a 3D system of qubits, works to reduce errors in just one dimension along a single line of connected qubits.
Error correction is performed by writing code that operates through the qubit structure, a latticework of how the ‘quantum switches’ are organised.
The objective is to win an ‘arms race’ where physical qubits are used to suppress errors as they emerge, by using as few qubits as possible to reduce errors.
Current 3D codes in a block of dimensions L x L x L can only manage L errors, but the new codes can handle errors that scale like L2 (LxL) - a significant improvement.
It has been known for more than a decade that a three-dimensional quantum error correction architecture (LxLxL) had an upper limit of LxL, but no such codes had been discovered.
“This means that we have discovered new states of quantum matter in three dimensions that have properties never seen before,” PhD student and co-author Nouédyn Baspin said.
“There remain significant barriers to overcome in the development of a universal quantum computer,” said researcher Dr Dominic Williamson from the University of Sydney Nano Institute.
“One of the biggest is the fact we need to use most of the qubits - quantum switches at the heart of the machines - to suppress the errors that emerge as a matter of course within the technology.
“Our proposed quantum architecture will require fewer qubits to suppress more errors, liberating more for useful quantum processing,” said Dr Williamson, who is currently working for 12 months as a quantum researcher at IBM.
Williamson and Baspin’s research introduces a three-dimensional architecture that effectively manages quantum errors within two-dimensional layers.
By leveraging this three-dimensional topological code, the researchers have demonstrated that it is possible to achieve optimal scaling while significantly reducing the number of physical qubits needed.
This advance could be crucial for the development of scalable quantum computers, as it allows for a more compact construction of quantum memory systems.
By reducing the physical qubit overhead, the findings pave the way for the creation of a more compact "quantum hard drive” – an efficient quantum memory system capable of storing vast amounts of quantum information reliably.
The study has been published in Nature Communications.
