论文标题
光子lieb-kagome晶格中的倾斜狄拉克锥和不对称锥形衍射
Tilted Dirac cones and asymmetric conical diffraction in photonic Lieb-kagome lattices
论文作者
论文摘要
Lieb Lattice和Kagome Lattice都以狄拉克锥和扁平带而闻名，可以通过剪切转换不断地转换为彼此。在这种转换过程中，平坦的频带被破坏，但狄拉克锥留下并倾斜，型I，II和III型出现在不同的参数中。在这项工作中，我们首先使用紧密结合模型研究了这些倾斜的狄拉克锥，揭示了如何将它们设计到不同类型的类型中。然后，我们使用分裂束传播模拟在光子晶格实现光子晶格实现中证明了锥形衍射，获得了朝不同方向倾斜的狄拉克锥的证据。最后，我们用融合二氧化硅（Sio $ _2 $）的光子晶格激光写的光子晶格进行了实验，以验证模拟的结果。这些研究一般来说，提高了对Lieb-Kagome晶格和倾斜的Dirac锥的理解，并为进一步研究这个有趣的可调晶格系统提供了基础。
The Lieb lattice and the kagome lattice, which are both well known for their Dirac cones and flat bands, can be continuously converted into each other by a shearing transformation. During this transformation, the flat band is destroyed, but the Dirac cones remain and become tilted, with types I, II, and III occurring for different parameters. In this work, we first study these tilted Dirac cones using a tight-binding model, revealing how they can be engineered into the different types. We then demonstrate conical diffraction in a photonic lattice realization of the Lieb-kagome lattice using split-step beam propagation simulations, obtaining evidence of the presence of Dirac cones tilted in different directions. Finally, we performed experiments with photonic lattices laser-written in fused silica (SiO$_2$) to validate the results of the simulations. These studies advance the understanding of the Lieb-kagome lattice and tilted Dirac cones in general and provide a basis for further research into this interesting tunable lattice system.
