标题： 选择性生长的拓扑绝缘体纳米带中的相位相干环路 显示英文标题

标题： Phase-coherent loops in selectively-grown topological insulator nanoribbons

摘要： 普遍电导涨落和弱反局域效应是磁电导中由电子干涉引起的缺陷结构特异性特征。 实验证据表明，目前拓扑绝缘体（Bi$_{0.57}$Sb$_{0.43}$)$_2$Te$_3$纳米带的电导涨落是由定义明确且分辨清晰的相位相干环引起的，这些纳米带是通过分子束外延选择性生长的。 从不同磁场倾斜角度的测量中推断出，这些环优先沿着拓扑绝缘体材料的五重层取向。 通过对普遍电导涨落的理论分析以及在低温下测量的弱反局域效应，提取了电子相位相干长度$l_\phi$，发现在前一种情况下更大。 讨论了这种偏差的可能原因。 显示英文摘要

摘要： Universal conductance fluctuations and the weak antilocalization effect are defect structure specific fingerprints in the magnetoconductance that are caused by electron interference. Experimental evidence is presented that the conductance fluctuations in the present topological insulator (Bi$_{0.57}$Sb$_{0.43}$)$_2$Te$_3$ nanoribbons which are selectively grown by molecular beam epitaxy are caused by well-defined and sharply resolved phase-coherent loops. From measurements at different magnetic field tilt angles we deduced that these loops are preferentially oriented parallel to the quintuple layers of the topological insulator material. Both from a theoretical analysis of universal conductance fluctuations and from weak antilocalization measured at low temperature the electronic phase-coherence lengths $l_\phi$ are extracted, which is found to be larger in the former case. Possible reasons for this deviation are discussed.