Observation of supersymmetric pseudo-Landau levels in strained microwave graphene
Observation of supersymmetric pseudo-Landau levels in strained microwave graphene
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DOI：
10.1038/s41377-020-00351-2
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发表时间：
2020-08-19
影响因子：
19.4
通讯作者：
Schomerus, Henning
中科院分区：
文献类型：
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作者：
Bellec, Matthieu;Poli, Charles;Schomerus, Henning
使用排列在变形蜂窝晶格中的耦合微波谐振器阵列，我们实验观察到从消失到大伪磁场强度的整个交叉中伪朗道能级的形成。这一结果是通过利用一个适应性的设置在一个几何形状，是兼容的伪朗道水平在所有的场强。所采用的方法使我们能够观察到完全形成的平带伪朗道能级光谱的光子态密度的尖峰和图像空间相关的波函数，在那里我们提供了明确的证据，反映了以前难以捉摸的超对称性的特征节点结构在底层的低能量理论。特别是，我们解决了完整的亚晶格极化的异常的第0伪朗道水平，这揭示了一个深刻的连接到锯齿形边缘状态在无应变的情况下。光子学：加深我们对材料拓扑状态的理解更深入地了解石墨烯类结构的拓扑状态如何影响其光学特性，可以为平带激光器和新型传感器等应用铺平道路。材料的拓扑状态可以为它提供不寻常的属性。例如，拓扑绝缘体可以在其内部充当绝缘体，但允许电流在其表面上以相反的方向流动。类似的特性也可以被设计到光学系统中。结合英国兰开斯特大学的Henning Schomerus领导的理论，以及法国蔚蓝海岸大学的Matthieu Bellec和Fabrice Mortessagne进行的实验，一组研究人员已经证明了石墨烯光子类似物中变形的应用如何导致伪朗道能级的形成。这项工作表明，材料的边缘和体积特性与子晶格极化直接相关，并提供了一个统一的原理，连接了各种各样的拓扑现象。
Using an array of coupled microwave resonators arranged in a deformed honeycomb lattice, we experimentally observe the formation of pseudo-Landau levels in the whole crossover from vanishing to large pseudomagnetic field strengths. This result is achieved by utilising an adaptable setup in a geometry that is compatible with the pseudo-Landau levels at all field strengths. The adopted approach enables us to observe the fully formed flat-band pseudo-Landau levels spectrally as sharp peaks in the photonic density of states and image the associated wavefunctions spatially, where we provide clear evidence for a characteristic nodal structure reflecting the previously elusive supersymmetry in the underlying low-energy theory. In particular, we resolve the full sublattice polarisation of the anomalous 0th pseudo-Landau level, which reveals a deep connection to zigzag edge states in the unstrained case. Photonics: Deepening our understanding of a material's topological statesA deeper understanding of how the topological states of graphene-like structures affect their optical properties could pave the way for applications such as flat-band lasers and novel sensors. A material's topological state can provide it with unusual properties. For example, topological insulators can act as insulators in their interior but allow currents to flow in opposite directions on their surface. Similar properties can also be engineered into optical systems. Combining theory led by Henning Schomerus from Lancaster University in the United Kingdom, and experiments carried out by Matthieu Bellec and Fabrice Mortessagne from Universite Cote d'Azur in France, a team of researchers has demonstrated how the application of a deformation in a photonic analogue of graphene results in the formation of pseudo-Landau levels. The work shows that the material's edge and bulk properties and sub-lattice polarisation are directly linked and provides a unifying principle that connects a wide variety of topological phenomena.