论文标题
带绝缘子到Mott绝缘子过渡，1T-TAS $ _2 $
Band insulator to Mott insulator transition in 1T-TaS$_2$
论文作者
论文摘要
1T-TAS $ _2 $在冷却后经历了连续的阶段过渡，并最终进入了神秘起源的绝缘状态。有些人认为该状态是带有层间堆叠顺序的带绝缘子，而另一些则将其归因于支持量子旋转液态状态的Mott物理学。在这里，我们确定了使用角度分辨的光发射光谱光谱和X射线衍射的1T-TAS $ _2 $的电子和结构特性。在低温下，2 $π$/2C - 周期性带分散体，以及沿C轴的半数指数衍射峰，明确表明1T-TAS $ _2 $的基态是带有夹层层化的带绝缘子。但是，加热后，系统经历了一个过渡到莫特绝缘状态，仅在狭窄的温度窗口中存在。我们的结果反驳了仅在低温下仅在1T-TAS $ _2 $中搜索量子磁性的想法，并强调了现场库仑排斥和跳层跳跃之间的竞争，这是了解材料电子特性的关键方面。
1T-TaS$_2$ undergoes successive phase transitions upon cooling and eventually enters an insulating state of mysterious origin. Some consider this state to be a band insulator with interlayer stacking order, yet others attribute it to Mott physics that support a quantum spin liquid state.Here, we determine the electronic and structural properties of 1T-TaS$_2$ using angle-resolved photoemission spectroscopy and X-Ray diffraction. At low temperatures, the 2$π$/2c-periodic band dispersion, along with half-integer-indexed diffraction peaks along the c axis, unambiguously indicates that the ground state of 1T-TaS$_2$ is a band insulator with interlayer dimerization. Upon heating, however, the system undergoes a transition into a Mott insulating state, which only exists in a narrow temperature window. Our results refute the idea of searching for quantum magnetism in 1T-TaS$_2$ only at low temperatures, and highlight the competition between on-site Coulomb repulsion and interlayer hopping as a crucial aspect for understanding the material's electronic properties.
