Rydberg Ions Achieve 97% Fidelity with Fast Three-Qubit Gates for Quantum Computing
A team of researchers in China has developed a faster, more accurate quantum computing gate. The breakthrough uses excited ions to achieve over 97% precision in operations. This could bring practical quantum error correction a step closer to reality.
Scientists at the University of Science and Technology of China (USTC) led the project under Professor Pan Jianwei. Their work focused on trapped Rydberg ions, confined in a linear Paul trap. By exciting these ions into high-energy states, they created a gate that operates in just two microseconds—far quicker than traditional methods.
The team implemented a three-qubit gate with fidelity exceeding 97%. They used the Bacon-Shor code for error correction, a method known for its simplicity and reduced need for precise measurements. To overcome hardware limitations, fault-tolerant SWAP gates moved qubits within the trap, allowing the error correction circuit to function despite restricted connectivity. Their approach relies on a native controlled-controlled-Z gate, optimised for the short lifespan of Rydberg states. Strong, long-range dipole interactions in these excited ions enable rapid multi-qubit operations. While the logical error rates meet current standards for demonstrating quantum advantage, the researchers note that further improvements in physical gate accuracy are still required. The study also proposed and simulated a new fault-tolerant error correction method. This combines theoretical modelling with real-world hardware, showing how Rydberg ion traps could become a practical platform for scalable quantum computing.
The findings mark a significant step toward reliable quantum error correction. The gate’s speed and accuracy suggest potential for future quantum systems. However, reducing physical gate errors remains a key challenge before full-scale applications can be realised.
