In a first, Chinese team slows quantum chaos using 78-qubit processor

Scientists at the Institute of Physics, Chinese Academy of Sciences, have for the first time directly observed and controlled a critical intermediate stage in quantum systems called prethermalisation, using their 78-qubit superconducting processor, Chaung tzu 2.0. Prethermalisation is a transient phase during quantum decoherence where the system temporarily resists chaos and preserves quantum information before full thermalisation occurs. This discovery provides a crucial time window to maintain quantum information, addressing a major challenge in quantum computing where qubits lose information due to decoherence. The research highlights that prethermalisation is not only observable but also highly controllable. By applying tailored control sequences, the team successfully manipulated the duration and pattern of this phase, effectively tuning the quantum system’s resistance to chaos. This ability to control prethermalisation could lead to enhanced coherence times for qubits and improved quantum error correction methods. Moreover, the study demonstrates the power of quantum processors like Chaung tzu 2.0 to simulate complex quantum