近日，韩国延世大学的Jae Hoon Kim及其研究小组与美国罗格斯大学的Sang-Wook Cheong以及韩国科学技术院的Eun-Gook Moon等人合作，并取得一项新进展。经过不懈努力，他们发现了三角形晶格莫特绝缘体TbInO3中的非常规室温载流子。相关研究成果已于2023年8月17日在国际知名学术期刊《自然—物理学》上发表。
该研究团队提出了一种新的观点，使用太赫兹时域光谱技术证实，即使在室温下，TbInO3也存在外来载流子。这一发现使得TbInO3成为实现低温量子自旋液相的潜在候选材料。研究发现在1.5-300K的整个温度范围内，平面内光学电导率的实部呈现出二次频率依赖关系，同时与激发连续体强烈相互作用的光学声子模式表现出Fano不对称性。即使在高达7T的外部磁场下，这些特征也表现出极大的鲁棒性。该研究的数据证实了TbInO3的莫特电荷间隙内存在突现载流子，这表明在室温下探测和操纵高度纠缠的量子多体态是可行的。
据悉，莫特绝缘体材料中电子之间的强关联性可以产生具有非常规突现激发的高度纠缠多体态。通常这种激发的特征，如果有的话，被认为只能在低温下观察到。
附：英文原文
Title: Unconventional room-temperature carriers in the triangular-lattice Mott insulator TbInO3
Author: Jung, Taek Sun, Xu, Xianghan, Kim, Jaewook, Kim, Beom Hyun, Shin, Hyun Jun, Choi, Young Jai, Moon, Eun-Gook, Cheong, Sang-Wook, Kim, Jae Hoon
Issue&Volume: 2023-08-17
Abstract: The strong correlations between electrons in Mott insulator materials may produce highly entangled many-body states with unconventional emergent excitations. The signatures of such excitations, if any, are commonly believed to be observable only at low temperatures. Here, we challenge this common belief and show using terahertz time-domain spectroscopy that exotic carriers exist even at room temperature in TbInO3, a candidate material for realizing a low-temperature quantum spin-liquid phase. In particular, over the entire temperature range of 1.5–300K, we observe a quadratic frequency dependence in the real part of the in-plane optical conductivity as well as Fano asymmetry of an optical phonon mode strongly interacting with the excitation continuum. These features are robust even under external magnetic fields of up to 7T. Our data confirm the presence of emergent charge carriers within the Mott charge gap of TbInO3, suggesting that it is possible to probe and manipulate highly entangled quantum many-body states at room temperature.
DOI: 10.1038/s41567-023-02174-5
Source: https://www.nature.com/articles/s41567-023-02174-5