Observation of quantum temporal correlations well beyond Luders bound

• DOI: 10.48550/arxiv.2304.06590
• Publication Date: 2025-01-15
• Authors: Chun-Wang Wu; Man-Chao Zhang; Yan-Li Zhou; Ting Chen; Ran Huang; Yi Xie; Wen-bo Su; Bao-Quan Ou; Wei Wu; Adam Miranowicz; Franco Nori; Jie Zhang; Hui Jing; Ping-Xing Chen
• Keywords: Quantum Physics; Physics; QC1-999; FOS: Physical sciences; Quantum Physics (quant-ph)

The ability of achieving strong quantum spatial correlations has helped the emergence of quantum information science. In contrast, how to achieve strong quantum temporal correlations (QTCs) has remained as a long-standing challenge, thus hindering their applications in time-domain quantum control. Here we experimentally demonstrate that by using a parity-time (PT)–symmetric single ion, the conventional QTC limit known as the Lüders bound can be well surpassed within a standard measurement scenario, approaching the predicted maximum QTC value. Our work, as a step toward quantum engineering of PT devices in the time domain, can stimulate more efforts on operating various quantum devices with the aid of strong QTC resources. Published by the American Physical Society 2025