Antiferromagnetic phase transition observed in fermionic Hubbard model

A research team from the University of Science and Technology of China has reported observing antiferromagnetic phase transition in a large and uniform quantum simulator, according to a study published in the journal Nature.

The quantum simulator is the first to achieve the simulation of the fermionic Hubbard model beyond classical computers using ultracold atomic quantum simulators.

The international academic community has set three stages for the development of quantum computing. Chen Yu'ao, professor from the research team of University of Science and Technology of China, said that the first-level goal had been reached after the launch of Google's "Sycamore," China's University of Science and Technology's "Jiuzhang" series and the "Zuchongzhi" quantum computing platforms.

"The second-stage goal, also the current primary research goal, is to realize dedicated quantum simulators for solving important scientific problems, such as the fermionic Hubbard model," said Chen. "Therefore, constructing a quantum simulator to verify phenomena like antiferromagnetic phase transitions is the first step towards achieving a dedicated quantum simulator capable of solving the fermionic Hubbard model. The third-stage goal is to achieve fault-tolerant universal quantum computers with the assistance of quantum error correction."

Based on former researches, the team further developed the flat-top optical lattice technology, allowing for precise control of strength, temperature and doping concentration. This has led to direct observation of conclusive evidence, thus verifying for the first time the antiferromagnetic phase transition of the fermionic Hubbard model under doping conditions.