标题： 层叠石墨烯的非线性光学响应和自发极化行为的二次谐波生成研究 显示英文标题

标题： Nonlinear optical response and spontaneous polarization in layer-stacked gallenene using second harmonic generation

摘要： 石墨烯是一种具有单原子厚度结构的有前途的低维材料，类似于石墨烯。 然而，在受限条件下二维（2D）石墨烯的范德华堆叠仍知之甚少。 在本研究中，我们提供了在液态镓中形成平行堆叠六方石墨烯（a100）结构的证据。 本研究通过透射电子显微镜展示了夹在两层石墨烯之间的二维石墨烯a100晶体的AB堆叠。 通过二次谐波生成（SHG）显微镜研究了受限六方石墨烯的非线性光学响应。 SHG信号在角度旋转至90度时表现出周期性峰强度偏移，并在温度升高时强度减弱。 这些发现为二维石墨烯的器件应用提供了见解。 显示英文摘要

摘要： Gallenene is a promising low-dimensional material with a structure down to the thickness of a single atom, similar to graphene. However, van der Waals stacking of two-dimensional (2D) gallenene under confinement remain poorly understood. In this study, we present evidence of the formation of parallel-stacked hexagonal gallenene (a100) structures in liquid gallium. The present study demonstrates the AB stacking of 2D gallenene a100 crystals in liquid gallium sandwiched between two graphene layers, as observed through transmission electron microscopy. A nonlinear optical response of the confined hexagonal gallenene was investigated through second harmonic generation (SHG) microscopy. The SHG signal exhibits periodic peak intensity shifts upon angular rotation up to 90 degrees and intensity dampening at elevated temperatures. These findings offer insights on device applications of 2D gallenene.