Research Group Makes Progress in the study of quantum control of dissipative systems, Published in Physical Review Letters
Recently, a collaborative study by Professor Hu Ying and Professor Shen Heng from the research group has made a significant breakthrough in the field of quantum control of dissipative systems. The related research, entitled "Realizing exceptional points by Floquet dissipative couplings in thermal atoms," was published in Physical Review Letters on September 26. The lead author of the paper is doctoral student Zhang Zimo, with Associate Professor Xu Zhongxiao, Professor Hu Ying from the Institute of Laser Spectroscopy, and Dr. Bao Han from Johannes Gutenberg University Mainz serving as corresponding authors. Among them, Professor Hu Ying and Dr. Bao Han provided crucial theoretical support, while Professor Shen Heng proposed and designed the research topic.
Exceptional degeneracies and generically complex spectra of non-Hermitian systems are at the heart of numerous phenomena absent in the Hermitian realm. Recently, it was suggested that Floquet dissipative coupling in the space-time domain may provide a novel mechanism to drive intriguing spectral topology with no static analogs, though its experimental investigation in quantum systems remains elusive. We demonstrate such Floquet dissipative coupling in an ensemble of thermal atoms interacting with two spatially separated optical beams, and observe an anomalous anti-parity-time symmetry phase transition at an exception point far from the phase-transition threshold of the static counterpart. Our protocol sets the stage for Floquet engineering of non-Hermitian topological spectra, and for engineering new quantum phases that cannot exist in static systems.
