Two theorists in quantum information have addressed a long-standing issue that could enhance quantum computing capabilities.
Researchers Dominic Williamson and Nouédyn Baspin from the University of Sydney have unveiled a groundbreaking new design for error management in quantum computers.
Their novel theoretical framework not only aims to improve the reliability of quantum information storage but also seeks to greatly decrease the physical resources required for creating ‘logical qubits’ (or quantum switches that execute valuable computations). This can facilitate the development of a more compact “quantum hard drive.”
Dr. Dominic Williamson, the lead author from the University of Sydney Nano Institute and School of Physics, mentioned, “There are still significant hurdles to overcome in creating a universal quantum computer. One of the primary challenges is that most of the qubits—quantum switches core to the machines—must be utilized just to mitigate inevitable errors that arise within this technology.”
“Our suggested quantum framework will use fewer qubits to correct more errors, allowing for more qubits to be available for practical quantum processing,” explained Dr. Williamson, who is currently engaged in a year-long quantum research position at IBM.
Their findings have been published in Nature Communications.
Central to their theoretical design is a three-dimensional framework that enables quantum error correction across two dimensions. Whereas current error correction designs, also structured in 3D, focus on reducing errors along a single line of linked qubits, this new model operates differently.
Error correction involves utilizing code to navigate through the qubit configuration, a network illustrating how the ‘quantum switches’ are arranged. The aim is to win an “arms race” wherein physical qubits are employed to mitigate errors as they occur, while utilizing the fewest number of qubits possible.
Dr. Williamson commented, “Existing 3D codes with dimensions L x L x L can only manage L errors. Our codes can accommodate errors scaling like L2 (LxL)—a substantial enhancement.”
It has been established for over a decade that a three-dimensional quantum error correction system (LxLxL) has an upper constraint of LxL, yet no codes matching this capability had been found.
PhD student and co-author Nouédyn Baspin stated, “This signifies that we have identified new forms of quantum matter in three dimensions with unprecedented properties.”
Quantum computers hold the potential to solve intricate problems that are out of reach for classical computers. However, a key obstacle in achieving practical quantum computing is the requirement for effective error correction methods.
Traditional quantum error correction strategies, like the extensively researched surface code, encounter limitations regarding scalability and resource efficiency.
Williamson and Baspin’s study introduces a three-dimensional framework that adeptly controls quantum errors within two-dimensional layers. By utilizing this three-dimensional topological code, they have shown that it is feasible to attain optimal scaling while significantly decreasing the number of physical qubits required. This development is vital for creating scalable quantum computers, allowing for a more compact design of quantum memory systems.
By minimizing the physical qubit demand, these discoveries open the path for a more compact “quantum hard drive”—an effective quantum memory system capable of reliably storing vast amounts of quantum data.
Professor Stephen Bartlett, a quantum theorist and Director of the University of Sydney Nano Institute, stated, “This advancement has the potential to revolutionize how quantum computers are constructed and utilized, making them more accessible and practical for various applications, ranging from cryptography to complex simulations of quantum many-body systems.”
