论文标题
压电二维材料中的非线性激子漂移
Nonlinear exciton drift in piezoelectric two-dimensional materials
论文作者
论文摘要
单层过渡金属二分法的非中心性质在有限的压电性和山谷齐曼耦合中表现出来。我们在过渡金属二甲化合物的单层纳米泡中进行了显微镜模拟非线性激子的转运。多亏了巨大的压电效果，我们获得了一个巨大的内部电场，$ e _ {\ rm piezo} \ sim 10^7 $ v/m，从而产生了激子的内置偶极矩。我们证明，压电诱导的偶极 - 偶极相互作用为非线性激子转运提供了一个新的通道，与传统的激发激素的各向同性漏斗不同，并导致在圆形对称的纳米泡中形成六边形的激子液滴。该效果可通过压电大小的依赖性调谐，带有$ h _ {\ rm max max} $和$ r $的气泡高度和$ r $，分别是气泡高度和radius，用$ h _ {\ rm _ {\ rm max}/rm max}/rm max}/rm max}/rm max}/rm max}/rm max}/rm max}/rm max}/rm max}/rm^3 $调节。
Noncentrosymmetric nature of single-layer transition metal dichalcogenides manifest itself in the finite piezoelectricity and valley-Zeeman coupling. We microscopically model nonlinear exciton transport in nano-bubble of single-layers of transition metal dichalcogenide. Thanks to the giant piezoelectric effect, we obtain an enormous internal electric field, $E_{\rm piezo}\sim 10^7$V/m, resulting in a built-in dipole moment of excitons. We demonstrate that the piezo-induced dipole-dipole interaction provides a novel channel for the nonlinear exciton transport distinct from the conventional isotropic funneling of excitons and leading to the formation of hexagon-shaped exciton droplet on top of a circularly symmetric nano-bubble. The effect is tunable via the bubble size dependence of the piezo-electric field $E_{\rm piezo} \sim h^2_{\rm max}/R^3$ with $h_{\rm max}$ and $R$ being the bubble height and radius, respectively.
