标题： 量子自旋霍尔绝缘体中边缘电流的磁场表征 显示英文标题

标题： Magnetic field Characterization of edge currents in quantum spin Hall insulators

摘要： 量子自旋霍尔（QSH）绝缘体是具有非平凡拓扑性质的材料，其特征是螺旋状的边缘电流。 在二维条带中，沿边缘施加偏置电压会产生磁化，可以使用量子传感器和磁力测量技术进行测量。 在本工作中，我们计算了边缘附近的磁场，并探讨了金刚石中的氮空位（NV）中心作为拓扑绝缘体中QSH边缘态表征的局部探针的潜力。 我们表征了由边缘电子电流和边缘自旋积累产生的边缘附近的磁场。 我们专注于确定从边缘开始的哪个位置自旋积累的影响变得可检测。 我们观察到，导带和价带之间的较大禁带宽度以及较低的费米速度会导致更强的磁场，可检测的自旋积累更集中在边缘附近。 相反，较小的禁带宽度会导致磁场强度略有减小，但与自旋积累相关的磁场在离边缘更远的位置变得可检测。 这项工作提供了可能对拓扑材料的表征和新型电光器件的发展有用的见解。 显示英文摘要

摘要： Quantum spin Hall (QSH) insulators are materials with nontrivial topological properties, characterized by helical edge currents. In 2D strips, the application of a bias voltage along the edge generates a magnetization that can be measured using quantum sensors and magnetometry techniques. In this work, we calculate the magnetic field in the vicinity of the edge and explore the potential role of nitrogen-vacancy (NV) centers in diamond as local probes for the characterization of QSH edge states in topological insulators. We characterize the magnetic field near the edges produced by both electron currents and spin accumulation at the edge. We focus on identifying the position from the edge at which the effects of spin accumulation become detectable. We observe that a larger gap between the conduction and valence bands, along with a lower Fermi velocity, results in a stronger magnetic field, with the detectable spin accumulation being more concentrated near the edge. Conversely, a smaller gap results in a slight reduction in the magnetic field magnitude, but the field associated with spin accumulation becomes detectable further from the edge. This work provides insights that could be useful for the characterization of topological materials and the development of novel electro-optical devices.