论文标题
超快触发二维vse $ _2 $中绝缘子 - 金属过渡
Ultrafast triggering of insulator-metal transition in two-dimensional VSe$_2$
论文作者
论文摘要
在二维（2D）限制下的组装过渡金属二分法（TMDC）是一种有前途的方法，用于调整诸如超导性或电荷密度波（CDW）之类的物质状态。在这方面，单层（SL）vse $ _2 $在这方面脱颖而出，因为它表现出强烈的CDW过渡，并且与散装相比，除了绝缘阶段，在费米水平上具有各向异性差异，从而导致预期的材料中预期的2D Ferromagnetism抑制了Anisotropic GAP。在这里，我们使用Ultrafast Pump-Probe-Probobe光发射光谱法研究了这些电子相位的电子和晶格自由度的相互作用，这些相互作用是SL VSE $ _2 $的基础。在绝缘状态下，我们观察到在480 fs的时间尺度上的光引起的闭合，我们将其从随后的热载体动力学中解脱出来。因此，我们的工作表明，SL VSE $ _2 $中的相变是由电子晶体耦合驱动的，并证明了在2D材料中使用光的2D材料控制电子相的潜力。
Assembling transition metal dichalcogenides (TMDCs) at the two-dimensional (2D) limit is a promising approach for tailoring emerging states of matter such as superconductivity or charge density waves (CDWs). Single-layer (SL) VSe$_2$ stands out in this regard because it exhibits a strongly enhanced CDW transition with a higher transition temperature compared to the bulk in addition to an insulating phase with an anisotropic gap at the Fermi level, causing a suppression of anticipated 2D ferromagnetism in the material. Here, we investigate the interplay of electronic and lattice degrees of freedom that underpin these electronic phases in SL VSe$_2$ using ultrafast pump-probe photoemission spectroscopy. In the insulating state, we observe a light-induced closure of the energy gap on a timescale of 480 fs, which we disentangle from the ensuing hot carrier dynamics. Our work thereby reveals that the phase transition in SL VSe$_2$ is driven by electron-lattice coupling and demonstrates the potential for controlling electronic phases in 2D materials with light.
