Wedoany.com Report on Feb 7th, The Quantum Device Lab at ETH Zurich has achieved a significant breakthrough in the field of superconducting quantum computing. Led by Professor Andreas Wallraff from D-PHYS, the team, in collaboration with the Paul Scherrer Institute, RWTH Aachen University, and Forschungszentrum Jülich, has for the first time successfully demonstrated the "lattice surgery" technique in a superconducting qubit system, realizing fault-tolerant quantum operations between logical qubits. This research marks an important step from quantum error correction theory towards practical application, and the related paper has been officially published in the top international journal *Nature Physics*. 
In the experiment, the team employed a surface code-based quantum error correction scheme, encoding 17 physical qubits into a single logical qubit, and dynamically splitting it into two entangled logical qubits using the lattice surgery technique. Throughout the operation, the system read out stabilizers every 1.66 microseconds while continuously executing error correction procedures for bit-flip and phase-flip errors. Particularly during the splitting operation, the researchers ingeniously read the states of three key data qubits in the middle of the square array while temporarily halting the measurement of X-type stabilizers. This ultimately succeeded in preparing two logical qubits in an entangled state, achieving scalable manipulation of quantum information.
Postdoctoral researcher Dr. Ilia Besedin pointed out that lattice surgery is a fundamental operation that can serve as a building block to support more complex quantum logic computing architectures. Co-lead author Michael Kerschbaum emphasized that this is the first time this operation has been realized on a superconducting qubit platform, effectively breaking through the limitations of traditional fixed two-dimensional qubit layouts and opening up a new technical pathway for achieving fault-tolerant computing in superconducting systems.
Although the current experiment can only completely correct bit-flip errors—fully suppressing phase-flip errors would still require scaling the system to 41 physical qubits—this demonstration has clearly verified the feasibility of lattice surgery on actual hardware. This achievement is not only an important milestone in the development of quantum error correction technology but also lays a crucial foundation for building large-scale, scalable, and practical quantum computers in the future, accelerating the process of efficient quantum algorithm execution in real physical systems.
This breakthrough demonstrates the strong potential of superconducting quantum systems in realizing fault-tolerant quantum computing, propelling the global quantum technology field across a significant leap from laboratory research to engineering applications.
