Chinese scientists have made significant progress toward developing a large-scale quantum computer by constructing the world's largest quantum simulation machine using the "trapped-ion" technique. This achievement hailed as a "milestone to be recognized" by an academic journal reviewer, was led by renowned quantum physicist Duan Luming.
Duan returned to China in 2018 after spending 15 years teaching in the United States. He earned his doctorate in 1998 from the University of Science and Technology of China, a leading institution in quantum research, before joining the University of Michigan in the early 2000s. Since his return, Duan has been a full-time professor at Tsinghua University’s Institute for Interdisciplinary Information Sciences.
Duan, along with his colleagues and several international research groups at universities and high-tech companies, has been exploring the trapped-ion approach to qubits. Qubits, or quantum bits, are fundamental to quantum computers, much like bits in traditional computers. However, harnessing qubits is challenging due to their uncertain and probabilistic nature. Unlike regular bits, which are either on or off, qubits can exist simultaneously in multiple states.
Trapped ions, or charged atomic particles, can be suspended in free space using electromagnetic fields. The qubits are stored in the stable electronic states of these ions, and quantum information is transferred through the collective motion of the ions within a shared trap. Scalability is a significant challenge in this system, but the trapped-ion approach offers one of the most promising architectures for a scalable, universal quantum computer.
Previously, researchers achieved quantum simulations with up to 61 ions in a one-dimensional crystal. These ion crystals are solids composed of ions arranged in a regular lattice structure. Duan and his team's quantum simulator, however, successfully achieved the stable trapping and cooling of a two-dimensional crystal with up to 512 ions, marking a scientific first. This breakthrough is crucial for the future of quantum computing, as scalability remains a primary obstacle. The team's ability to scale up the ions in a stable simulation system is expected to advance the development of more powerful quantum computers.
