1,000 times faster operations bring reliable quantum computing a step closer

Quantum computers have faced significant hurdles due to their extreme sensitivity to errors and external disturbances. A longer duration for quantum operations increases the risk of computational errors. Researchers at Chalmers University of Technology in Sweden have developed a groundbreaking method that allows advanced quantum operations to be carried out more than 1,000 times faster than before. This breakthrough addresses a well-known bottleneck and paves the way for fault-tolerant quantum computing.

Quantum computers hold immense potential for breakthroughs in various fields such as drug discovery, energy systems, cryptography, artificial intelligence, and logistics. However, before realizing this potential, they must become far more reliable. One major challenge lies in the computational errors that arise during quantum computing due to environmental disturbances like electrical noise, cosmic radiation, or overheating.

Conventional computers can handle such errors with established error-correction techniques, but quantum computers face a far greater challenge as their fundamental building blocks, qubits, are highly sensitive to even the slightest disturbances.

Bosonic quantum codes, which encode information in microwave fields within superconducting circuits, have shown promise in providing stronger protection against certain types of errors. However, implementing these quantum operations is notoriously difficult and time-consuming. Previous methods required quantum systems to be guided through thousands of repetitive driving cycles, leaving ample opportunity for errors to occur.

The researchers at Chalmers University have now developed an innovative approach that significantly speeds up these operations.

By devising a method that can perform a wide range of quantum operations on bosonic states within a single driving cycle, the researchers have not only made the process faster but also more efficient and less prone to errors caused by disturbances. This approach relies on the use of quantum lattice gates, a new universal quantum gate set recently proposed by the same research team. These gates function like prebuilt Lego modules that can be connected quickly and efficiently, much like building a large Lego castle.

The method is particularly suited for superconducting quantum computers, which are leading platforms in the global race toward large-scale quantum computing. It can also be implemented using existing superconducting quantum circuit platforms, similar to the 100-qubit quantum computer currently under development at Chalmers University of Technology. The key advantage of this approach is its ability to be realized using current technology, with the researchers already discussing possible experimental realizations.

This breakthrough addresses one of the major bottlenecks in the field by providing a quick and reliable way to create and control error-correcting quantum states. Bosonic quantum codes, which store quantum information in the states of microwave or optical resonators, are considered a promising tool for quantum error correction due to their built-in protection against certain types of errors.

By implementing quantum lattice gates, a wide range of complex quantum operations can be realized through Floquet control, a method that uses periodic control signals to drive a quantum system. The new Chalmers University method can directly implement these gates within a single driving cycle, making some operations more than 1,000 times faster than previous approaches.