Measuring topology in a laser-coupled honeycomb lattice: from Chern insulators to topological semi-metals
Measuring topology in a laser-coupled honeycomb lattice: from Chern insulators to topological semi-metals
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DOI：
10.1088/1367-2630/15/1/013025
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发表时间：
2013-01-14
影响因子：
3.3
通讯作者：
Juzeliunas, G.
中科院分区：
文献类型：
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作者：
Goldman, N.;Anisimovas, E.;Juzeliunas, G.
超冷费米子被困在一个蜂窝状的光学晶格构成了一个通用的设置，以实验实现的Halfton模型（1988年物理评论Lett。61 2015）。在该系统中，可以通过激光诱导方法设计非均匀的合成磁通量，明确打破时间反演对称性。这可能会在能谱中打开一个与非平凡拓扑序（即非零陈氏数）相关的体隙。在本文中，我们考虑的可能性，生产和识别这样一个强大的陈氏绝缘体的激光耦合蜂窝晶格。我们探索了一个大的参数空间跨越实验可控参数，并获得了各种相图，清楚地识别可访问的拓扑非平凡制度。我们讨论了冷原子系统中的陈氏绝缘体的签名，考虑可用的检测方法。我们还强调存在的拓扑半金属在这个系统中，这是无间隙的相位，其特征在于非零绕组数，不存在于Halfman的原始模型。
Ultracold fermions trapped in a honeycomb optical lattice constitute a versatile setup to experimentally realize the Haldane model (1988 Phys. Rev. Lett. 61 2015). In this system, a non-uniform synthetic magnetic flux can be engineered through laser-induced methods, explicitly breaking time-reversal symmetry. This potentially opens a bulk gap in the energy spectrum, which is associated with a non-trivial topological order, i.e. a non-zero Chern number. In this paper, we consider the possibility of producing and identifying such a robust Chern insulator in the laser-coupled honeycomb lattice. We explore a large parameter space spanned by experimentally controllable parameters and obtain a variety of phase diagrams, clearly identifying the accessible topologically non-trivial regimes. We discuss the signatures of Chern insulators in cold-atom systems, considering available detection methods. We also highlight the existence of topological semi-metals in this system, which are gapless phases characterized by non-zero winding numbers, not present in Haldane's original model.