In an experimental demonstration using a superconducting processor named Zuchongzhi 3.2, China has announced a significant advance in quantum error correction, dubbed “quantum supremacy 2.0.”
Zuchongzhi 3.2 processor successfully drives a logic surface code qubit at a distance of 7.
The notable factor is that as the code spacing increases, the logic error rate decreases. This inverse relationship is a critical aspect of China’s latest quantum error correction technique, which rivals Google’s previous achievements with its Willow results.
What sets China’s claim apart is an entirely microwave leakage suppression architecture designed to minimize “leakage,” where qubits escape the computational states assumed by error-correcting codes.
Addressing leakage is critical as it can lead to correlated errors that traditional decoders have difficulty handling. This new method makes leakage control an important design consideration, as previous research also advocated its importance in maintaining clean surface code cycles.
While China’s results aim to match Google’s benchmarks, they do not yet demonstrate the ability to run large calculations on multiple interacting logic qubits.
The transition from a single logical qubit to many presents complex technical challenges and new error paths.
IBM’s roadmap emphasizes that scaling to practical error-suppressing systems will require efficient codes and real-time decoding pipelines.
As the industry enters the “error correction era,” the focus is shifting to make error correction repeatable, automated, and economically scalable.
With several groups achieving subthreshold behavior, the next challenge is expected to lie in efficiently stacking logic qubits and maintaining manageable error budgets during actual computations.
