Topological insulators in the AIII (chiral unitary) symmetry class lack experimental realization. Moreover, fractionalization in one-dimensional topological insulators has not been yet directly observed. Our work might open possibilities for both challenges. We propose a one-dimensional model realizing the AIII symmetry class which can be realized in current experiments with ultracold atomic gases. We further report on a distinctive property of topological edge modes in the AIII class: in contrast to those in the well-studied BDI (chiral orthogonal) class, they have nonzero momentum. Exploiting this feature we propose a path for the detection of fractionalization. A fermion added to an AIII system splits into two halves localized at opposite momenta, which can be detected by imaging the momentum distribution.

中文翻译：

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实现和检测AIII对称等级的拓扑绝缘子

AIII（手性unit）对称性类的拓扑绝缘子缺乏实验实现。而且，还没有直接观察到一维拓扑绝缘体中的分级。我们的工作可能会为这两个挑战打开可能性。我们提出了一个实现AIII对称性类别的一维模型，该模型可以在当前的超冷原子气体实验中实现。我们进一步报告了AIII类中的拓扑边缘模式的独特性质：与经过深入研究的BDI（手性正交）类中的拓扑边缘模式相比，它们具有非零动量。利用此功能，我们提出了一种检测分级的路径。添加到AIII系统的费米子分为两个相反的半部分，可以通过对动量分布进行成像来检测。