Researchers at Chalmers University of Technology, Sweden, have identified a method to accelerate quantum computations by a factor of 1,000, bringing fault-tolerant quantum computers a significant step closer.
So far, quantum computers have been held back by their extreme sensitivity to errors and external disturbances, but a new method using ‘bosonic quantum codes’ offers a potential solution to this problem.
Bosonic quantum codes store quantum information in the states of microwave or optical resonators rather than in individual qubits. They are considered a promising tool for quantum error correction because they can provide built-in protection against certain types of errors.
However, quantum operations based on bosonic quantum codes are notoriously difficult to create and control.
Previous approaches that build up such quantum states each individual piece at a time have required quantum systems to be guided through thousands of repeated driving cycles, a time-consuming process that leaves more opportunity for errors to occur. Now, Chalmers researchers Lei Du and Tangyou Huang have developed an entirely new approach. Instead of building up quantum states step by step, they have devised a method that can perform these operations dramatically faster.
At the heart of the researchers’ approach are so-called quantum lattice gates, a new universal quantum gate set that was first proposed recently by the same research team. Functioning much like shortcut commands, these gates allow the desired operation to be completed within a single driving cycle, making the process both simpler and less prone to errors.
The method is particularly suited to superconducting quantum computers, one of the leading platforms in the global race towards large-scale quantum computing.
The research was funded by the National Natural Science Foundation of China (NSFC), the Wallenberg Centre for Quantum Technology (WACQT), and the Knut and Alice Wallenberg Foundation.
Resilience Forward comment
From a resilience perspective any advances in quantum computing need monitoring due to the issue of Q-day: the future point when quantum computers become powerful enough to break the cryptographic security that currently protects global digital infrastructure.
