Recently, a collaborative research project carried out by multiple teams achieved entangled logical qubits protected by quantum error correction within a superconducting quantum system. The teams were led by Luyan Sun, Changling Zou, and Haifeng Yu from Tsinghua University, University of Science and Technology of China, and Beijing Academy of Quantum Information Sciences, respectively. Their research paper titled "Protecting entanglement between logical qubits via quantum error correction" was published online in Nature Physics on March 6th, 2024.
Quantum error correction is a crucial issue in the field of quantum computing. It is well established that environmental noise significantly impacts the state of qubits, making quantum computations highly susceptible to errors from external disruptions. Quantum error correction protects quantum information from errors, offering a promising avenue for the practical realization of quantum computing. By introducing redundant degrees of freedom and constructing logical qubits using specific encoding schemes, quantum error correction can identify and correct errors without corrupting the original quantum information.
Currently, the quantum error correction techniques primarily rely on encoding schemes based on multiple two-level qubits, requiring a large number of physical qubits to encode a single logical qubit. This approach faces significant experimental challenges, such as the substantial increase of error channels as the quantity of physical qubits increases, and the need for intricate many-body interactions to detect and correct errors. To overcome these challenges, the research team led by Luyan Sun adopted a different encoding architecture based on single microwave resonators, known as bosonic encoding. This scheme utilizes the infinite Hilbert space of resonators for redundant information encoding while keeping the types of error channels constant, significantly reducing hardware requirements and making it possible to achieve quantum error correction ahead of others.
In recent years, the team led by Luyan Sun has been dedicated to research on bosonic quantum error correction. Collaborating with the team led by Changling Zou, they were the first to experimentally implement bosonic binomial codes, successfully demonstrating repetitive quantum error correction for logical qubits and extending the life