Exciton-polaritons in flatland: Controlling flatband properties in a Lieb lattice
Exciton-polaritons in flatland: Controlling flatband properties in a Lieb lattice
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DOI：
10.1103/physrevb.102.121302
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发表时间：
2020-09-02
影响因子：
3.7
通讯作者：
Klembt, Sebastian
中科院分区：
文献类型：
--
作者：
Harder, Tristan H.;Egorov, Oleg A.;Klembt, Sebastian
近年来，新型的二维材料如石墨烯、铋和过渡金属二硫属化物由于其独特的物理性质而引起了人们的极大兴趣。然而，某些晶格几何形状，如Lieb晶格，不存在原子单层。幸运的是，一系列物理效应可以通过创建模拟这些二维材料的人造光子晶格转移到光子学领域。在这里，激子极化激元在半导体微腔提供了一个令人兴奋的机会，研究一个复杂的晶格势的光的部分光，部分物质的量子流体。在这个快速通信中，我们研究了埋有光阱的二维Lieb晶格中的激子-极化激元。这样的Lieb晶格的S和P-xy光子轨道引起两个平带的形成，这两个平带对于紧凑局域态的无畸变存储是最感兴趣的。通过使用控制良好的蚀刻和过度生长技术，我们设法控制的陷阱，以及具有很高的精度的网站耦合。这使我们能够在光谱上监测整个布里渊区的平坦带的平坦度。此外，我们还通过实验证明了这些平带可以在非共振激光激发下通过凝聚直接填充。最后，使用这种先进的设备的方法，我们证明了共振和确定性激发的平带模式的传输几何形状。我们的研究结果建立了激子极化激元系统作为一个高度可控的，光学多体系统研究平带效应和无畸变存储紧凑的局域态。
In recent years, novel two-dimensional materials such as graphene, bismuthene, and transition-metal dichalcogenides have attracted considerable interest due to their unique physical properties. However, certain lattice geometries, such as the Lieb lattice, do not exist as atomic monolayers. Fortunately, a range of physical effects can be transferred to the realms of photonics by creating artificial photonic lattices emulating these two-dimensional materials. Here, exciton-polaritons in semiconductor microcavities offer an exciting opportunity to study a part-light, part-matter quantum fluid of light in a complex lattice potential. In this Rapid Communication, we study exciton-polaritons in a two-dimensional Lieb lattice of buried optical traps. The S and P-xy photonic orbitals of such a Lieb lattice give rise to the formation of two flatbands which are of greatest interest for the distortion-free storage of compact localized states. By using a well controlled etch-and-overgrowth technique, we manage to control the trapping as well as the site couplings with great precision. This allows us to spectroscopically monitor the flatness of the flatbands across the full Brillouin zone. Furthermore, we demonstrate experimentally that these flatbands can be directly populated by condensation under nonresonant laser excitation. Finally, using this advanced device approach we demonstrate resonant and deterministic excitation of flatband modes in transmission geometry. Our findings establish the exciton-polariton systems as a highly controllable, optical many-body system to study flatband effects and for distortion-free storage of compact localized states.