论文标题
用手性声子在摩西$ _2 $/wse $ _2 $ heterobilayers翻转激烈的动力动量
Flipping exciton angular momentum with chiral phonons in MoSe$_2$/WSe$_2$ heterobilayers
论文作者
论文摘要
将量子数识别为标记基本激发的量子数对于正确描述固体中的光结合相互作用至关重要。在单层半导体过渡金属二盐元素（TMD）中，例如Mose $ _2 $或WSE $ _2 $，大多数光电子现象都可以通过对层沿正常层的旋转投影标记为电子和孔状态（s $ _z $）。相比之下，对于WSE $ _2 $/MOSE $ _2 $接口最近实验表明，将S $ _Z $作为量子数并不是一个好近似值，并且需要始终考虑旋转混合。在这里，我们认为这些系统的正确量子数不是s $ _z $，而是总角动量的$ z $ - 组件 - j $ _z $ = l $ _z $ _z $ + s $ _z $ - 与c $ _3 $ rotational lattication lattice Symortry相关联，假定半智能值相应的模量与不同的状态3.不同的状态。我们通过观察由手性光学声子介导的强间隔散射来实验验证这一结论，尽管携带角动量1，但它们引起了激动子的谐振间隔跃迁，角动量差为2。
Identifying quantum numbers to label elementary excitations is essential for the correct description of light-matter interaction in solids. In monolayer semiconducting transition metal dichalcogenides (TMDs) such as MoSe$_2$ or WSe$_2$, most optoelectronic phenomena are described well by labelling electron and hole states with the spin projection along the normal to the layer (S$_z$). In contrast, for WSe$_2$/MoSe$_2$ interfaces recent experiments show that taking S$_z$ as quantum number is not a good approximation, and spin mixing needs to be always considered. Here we argue that the correct quantum number for these systems is not S$_z$, but the $z$-component of the total angular momentum -- J$_z$ = L$_z$ + S$_z$ -- associated to the C$_3$ rotational lattice symmetry, which assumes half-integer values corresponding modulo 3 to distinct states. We validate this conclusion experimentally through the observation of strong intervalley scattering mediated by chiral optical phonons that -- despite carrying angular momentum 1 -- cause resonant intervalley transitions of excitons, with an angular momentum difference of 2.
