论文标题
在隧道耦合的范德华杂质中的四极激激体
Quadrupolar excitons in a tunnel-coupled van der Waals heterotrilayer
论文作者
论文摘要
强烈结合的激子及其之间的多体相互作用决定了2D半导体的范德华（VDW）异质结构中的光 - 物质相互作用。与基本颗粒不同，可以调整冷凝物质中的准粒子，例如激子，以改变其相互作用并实现新兴的量子相。在这里，使用WS $ _2 $/WSE $ _2 $/WS $ _2 $ HETEROTRILAYER，我们创建了一个相反定向的偶性激子的量子叠加 - 四极性激子 - 四边形激子 - 其中电子在ws $ _2 $ _2 $ _2 $ layers ins the lose -_2 $ _2 $ los local ins the losials ins the bole int localizes in wes $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ _2。与偶性激子相反，对称四极性激子仅在平面电场中进行红移，这与从头算的计算一致，从而在较高的场上重新获得了偶性特性。电场对杂交进行调节，并通过修饰激发功率波功能来控制寿命。与偶极激子相比，异性晶状体激子缺乏密度依赖性蓝移与四极相互作用一致。我们的结果将VDW Heterotrilayers作为一个野外可调平台，用于设计光 - 物质相互作用并探索自发订购的许多exciton阶段之间的量子相变。
Strongly bound excitons and many-body interactions between them determine light-matter interactions in van der Waals (vdW) heterostructures of 2D semiconductors. Unlike fundamental particles, quasiparticles in condensed matter, such as excitons, can be tailored to alter their interactions and realize emergent quantum phases. Here, using a WS$_2$/WSe$_2$/WS$_2$ heterotrilayer, we create a quantum superposition of oppositely oriented dipolar excitons - a quadrupolar exciton - wherein an electron is layer-hybridized in WS$_2$ layers while the hole localizes in WSe$_2$. In contrast to dipolar excitons, symmetric quadrupolar excitons only redshift in an out-of-plane electric field, consistent with ab initio calculations, regaining dipolar characteristics at higher fields. Electric field tunes the hybridization and allows for lifetime control through modification of the excitonic wavefunction. Lack of density-dependent blue shift of heterotrilayer excitons compared to dipolar excitons is consistent with quadrupolar interactions. Our results present vdW heterotrilayers as a field-tunable platform to engineer light-matter interactions and explore quantum phase transitions between spontaneously ordered many-exciton phases.
