发表机构
National Institute for Materials Science; Graduate School of Chemical Sciences and Engineering, Hokkaido University（物质材料研究机构; 北海道大学化学理工学研究科）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究WS2-MoS2-WS2横向双异质结中的一维四极激子，通过电场实现从四极态到偶极态的连续转换，并揭示了条带宽度对耦合的几何调控作用。
AI 中文摘要
两个相邻的横向界面为在单个半导体单层内控制一维电荷转移激子提供了空间自由度。我们利用具有屏蔽库仑相互作用的有效质量双粒子哈密顿量研究了一种II型WS2-MoS2-WS2双异质结。在零电场下，对于等效的左右界面，界面间耦合产生能量分裂的偶宇称和奇宇称激子态，每个态具有零永久偶极矩。垂直于界面的电场连续地将较低态从具有二次斯塔克位移的四极叠加态转变为以近似线性位移为主的单界面偶极激子。空间分辨计算给出了约104和100 meV的结合能、4.6 meV的双线分裂以及代表性1.5 nm MoS2条带的0.87 V/μm的交叉场。投影测试表明，最低的双线控制着该交叉附近的响应。条带宽度对耦合的调节远强于对结合能的调节，为低场斯塔克灵敏度提供了几何控制。这些结果建立了一条连续介质模型路径，用于实现电可重构的一维四极激子。
英文摘要
Two neighboring lateral interfaces provide a spatial degree of freedom for controlling one-dimensional charge-transfer excitons within a single semiconductor monolayer. We investigate a type-II WS2-MoS2-WS2 double heterojunction using an effective-mass two-particle Hamiltonian with a screened Coulomb interaction. For equivalent left and right interfaces at zero electric field,inter-interface coupling produces energetically split even- and odd-parity exciton states, each with zero permanent dipole. An electric field perpendicular to the interfaces continuously converts the lower state from a quadrupolar superposition with a quadratic Stark shift into a predominantly single-interface dipolar exciton with an approximately linear shift. The spatially resolved calculation gives binding energies of approximately 104 and 100 meV, a doublet splitting of 4.6 meV, and a crossover field of 0.87 V/um for a representative 1.5-nm MoS2 strip. Projection tests show that the lowest doublet controls the response near this crossover. Strip width tunes the coupling much more strongly than the binding energy, providing geometric control of the low-field Stark sensitivity. These results establish a continuum-model route to electrically reconfigurable one-dimensional quadrupolar excitons.
