[论文解读] Topological optical and phononic interface mode by simultaneous band inversion

O. Ortíz, Priya Priya+4 more|arXiv (Cornell University)|Jul 29, 2020

Mechanical and Optical Resonators参考文献 39被引用 34

一句话总结

作者设计 GaAs/AlAs 多层结构，同时对光子与声子带进行反转，以在 1.34 eV 光子与 18 GHz 声子处实现共定位界面模态，并通过实验验证，同时给出稳健光机械态的设计规则。

ABSTRACT

Interface modes have been widely explored in the field of electronics, optics, acoustics and nanophononics. One strategy to generate them is band inversion in one-dimensional superlattices. Most realizations of this type of topological states have so far been explored for a single kind of excitation. Despite its potential in the manipulation and engineering of interactions, platforms for the simultaneous topological confinement of multiple excitations remain an open challenge. GaAs/AlAs heterostructures exhibit enhanced optomechanical interactions due to the intrinsic colocalization of light and sound. In this work, we designed, fabricated, and experimentally studied a multilayered structure based on GaAs/AlAs. Due to the simultaneously inverted band structures for light and phonons, colocalized interface modes for both 1.34 eV photons and 18 GHz phonons appear. We experimentally validated the concept by optical reflectivity and coherent phonon generation and detection. Furthermore, we theoretically analyzed the performance of different topological designs presenting colocalized states in time-domain Brillouin scattering and deduce engineering rules. Potential future applications include the engineering of robust optomechanical resonators, compatible with the incorporation of active media such as quantum wells and quantum dots.

研究动机与目标

• 激发并实现能够同时约束光学与声学激发的拓扑界面模态。
• 在 GaAs/AlAs 异质结构中证明光与声界面模态的共定位的实验证据。
• 提供理论分析与工程规则，用于设计稳健的光机界面态。

提出的方法

• 设计并制造对光子与声子具有反转带结构的 GaAs/AlAs 多层异质结构。
• 通过光学反射测量表征界面模态。
• 生成并检测相干声子以确认声学界面模态。
• 理论分析不同的拓扑设计并推导时域布里可伦散射特征。
• 推导实现共定位光机态的工程规则。

实验结果

研究问题

• RQ1 单一异质结构中的同时带反转是否能够承载光子与声子的界面模态？
• RQ2 在 GaAs/AlAs 中哪些实验信号可以确认共定位的光学与声学界面态？

主要发现

• 由于同时带反转，出现对1.34 eV 光子和 18 GHz 声子共定位的界面模态。
• 光学反射测量验证界面模态的光学分量。
• 相干声子产生与检测验证界面模态的声学分量。
• 理论分析展示在不同拓扑设计中的性能及时域布里可伦散射信号。
• 推导出设计稳健的光机谐振器的工程规则，包括与量子阱/量子点等有源媒介的兼容性。