Hasaien Jiazila, Wu Yanling, Shi Mengzhu, Zhai Yanni, Wu Qiong, Liu Zheng, Zhou Yi, Chen Xianhui, Zhao Jimin
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
Proc Natl Acad Sci U S A. 2025 Mar 4;122(9):e2406464122. doi: 10.1073/pnas.2406464122. Epub 2025 Feb 25.
Charge density wave (CDW) material 1-TaS was proposed as a quantum spin liquid candidate, on which a cluster Mott insulator comes into being below the transition temperature. We report an experimental ultrafast generation and detection of the coherent amplitude mode (AM) of its CDW state. A salient feature emerges: The coherent CDW mode AM exhibits an unusual temperature dependence below 65 K, in addition to the temperature dependence observed in the 65 to 200 K range. This behavior suggests the enhancement of in-gap electronic excitations below 65 K and the emergence of a new phase of matter. Consequently, the intriguing quantum state leads to a crossover. Our investigation provides insights into understanding the interplay among various degrees of freedom in quantum materials.
电荷密度波（CDW）材料1-TaS被提议作为量子自旋液体候选材料，在转变温度以下会形成团簇莫特绝缘体。我们报告了其实验上对其CDW态的相干振幅模式（AM）的超快产生和探测。一个显著特征出现了：除了在65至200 K范围内观察到的温度依赖性外，相干CDW模式AM在65 K以下还表现出异常的温度依赖性。这种行为表明在65 K以下能隙内电子激发增强，并且出现了新的物相。因此，这种引人入胜的量子态导致了一种转变。我们的研究为理解量子材料中各种自由度之间的相互作用提供了见解。
