论文标题
使用非局部表面传输来识别轴突绝缘子
Using nonlocal surface transport to identify the axion insulator
论文作者
论文摘要
轴是一个假设但未检测到的粒子。最近，预测抗铁磁拓扑绝缘子MNBI $ _2 $ _4 $ $ _4 $可以托管斧头绝缘子，但是实验证据仍然难以捉摸。具体而言，据信轴突绝缘子在其顶部和底部表面携带“半量化”的手性电流。但是，精确衡量半量化是一项挑战。在这里，我们提出了一个非局部表面传输装置，其中可以将轴突绝缘子与正常绝缘体区分开，而无需精确测量半量化。更重要的是，我们表明，在无间隙的侧面表面和混乱开始时，在逼真的情况下，非局部表面运输是一种稳健的测量。此外，厚电极可用于MNBI $ _2 $ te $ _4 $厚膜的设备，从而增强了表面测量的可行性。该提案将对在拓扑物质中搜索轴突绝缘子和轴心的搜索有见地。
The axion is a hypothetical but experimentally undetected particle. Recently, the antiferromagnetic topological insulator MnBi$_2$Te$_4$ has been predicted to host the axion insulator, but the experimental evidence remains elusive. Specifically, the axion insulator is believed to carry "half-quantized" chiral currents running antiparallel on its top and bottom surfaces. However, it is challenging to measure precisely the half-quantization. Here, we propose a nonlocal surface transport device, in which the axion insulator can be distinguished from normal insulators without a precise measurement of the half-quantization. More importantly, we show that the nonlocal surface transport, as a qualitative measurement, is robust in realistic situations when the gapless side surfaces and disorder come to play. Moreover, thick electrodes can be used in the device of MnBi$_2$Te$_4$ thick films, enhancing the feasibility of the surface measurements. This proposal will be insightful for the search of the axion insulator and axion in topological matter.
