Li Yan-Chao, Zhou Yuan-Hang, Zhang Yuan, Lin Hai-Qing
Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China.
Zhejiang Institute of Modern Physics and School of Physics, Zhejiang University, Hangzhou, 310027, China.
Sci Rep. 2025 Feb 21;15(1):6277. doi: 10.1038/s41598-025-90248-0.
From the perspective of entanglement in low-lying excited states, a profound analysis was carried out regarding the quantum phase transitions within three models that fall outside the Landau-Ginzburg-Wilson (LGW) paradigm. In the context of the deconfined quantum critical point (DQCP) in a one-dimensional quantum spin chain, our findings demonstrate a tight correlation between the reconstruction of low-lying excitation spectra and the DQCP. The precise location of the critical point and its continuous nature can be signaled by the singular behaviors of the entanglement of the first-excited state. Moreover, in comparison with two types of Berezinskii-Kosterlitz-Thouless (BKT) phase transitions, the entanglement presents three different singularity characteristics. These characteristics not only unveil the essence of diverse symmetry types on either side of the DQCP but also expose the disparate causes underlying the formation of the two BKT type phase transitions.
从低激发态的纠缠角度出发，对三种不属于朗道 - 金兹堡 - 威尔逊（LGW）范式的模型中的量子相变进行了深入分析。在一维量子自旋链中的禁闭量子临界点（DQCP）背景下，我们的研究结果表明低激发态光谱的重构与DQCP之间存在紧密关联。临界点的精确位置及其连续性质可以通过第一激发态纠缠的奇异行为来表征。此外，与两种类型的贝雷津斯基 - 科斯特利茨 - Thouless（BKT）相变相比，纠缠呈现出三种不同的奇异特征。这些特征不仅揭示了DQCP两侧不同对称类型的本质，还揭示了两种BKT型相变形成背后的不同原因。
