论文标题
平面准二维通道中的拓扑保护增强了宽度
Enhanced topological protection in planar quasi-one-dimensional channels with periodically-modulated width
论文作者
论文摘要
我们研究一维（1D）和准1D周期结构，是Majorana结合状态的出现的可能平台，具有增强的鲁棒性和对系统不均匀性的鲁棒性。首先，使用简单的1D模型，我们分析得出了表征由周期电势产生的小键的有效参数。我们表明，对于足够强大的周期性电势，与均匀系统中的较高能量迷你班相比，托管MajoraNA绑定状态具有显着优势，包括增加拓扑间隙，增强对疾病的鲁棒性以及与拓扑超导性存在一致的参数空间区域的扩大。我们确定工程具有足够强大的周期性潜力的问题，作为实现有效的周期性1D结构的关键障碍。为了应对这一挑战，我们提出了基于在2D半导体异质结构中实现的准周期电位的有效实施，该通道接近与定期调制宽度的超导体条接近。我们对调制通道设备的数值研究与简单的1D模型显示出非常一致的一致性，它揭示了拓扑相图对超导体筛选相关的限制电位的细节非常不敏感，并证明了工程图案的2D结构代表了一种强大而多功能的方法，可实现强大的主要范围。
We study one dimensional (1D) and quasi-1D periodic structures as possible platforms for the emergence of Majorana bound states with enhanced robustness against disorder and system inhomogeneity. First, using a simple 1D model, we analytically derive the effective parameters characterizing the minibands generated by the periodic potential. We show that, for strong enough periodic potentials, the higher energy minibands hosting Majorana bound states have significant advantages compared to their counterparts in uniform systems, including increased topological gaps, enhanced robustness against disorder, and enlarged parameter space regions consistent with the presence of topological superconductivity. We identify the problem of engineering a strong enough periodic potential as a key roadblock to realizing efficient periodic 1D structures. To address this challenge, we propose an efficient implementation of the periodic potential based on quasi-1D channels realized in 2D semiconductor heterostructures proximity coupled to superconductor strips of periodically modulated width. Our numerical study of the modulated channel device shows excellent agreement with the simple 1D model, reveals a topological phase diagram that is quite insensitive to the details of the confining potential associated with screening by the superconductor, and demonstrates that engineering patterned 2D structures represents a powerful and versatile approach to realizing robust Majorana bound states.
