拓扑近藤绝缘体SmB6中的奇异电子性质

拓扑近藤绝缘体是一种本征的强关联拓扑电子体系，其体能隙来源于近藤关联效应。自2010年拓扑近藤绝缘体的理论概念被提出后，六硼化钐(SmB6) 作为第一种被预测为拓扑近藤绝缘体的材料在这十多年中被多种实验手段反复研究验证，被广泛接受认为是第一种拓扑近藤绝缘体。在这篇综述中，我们回顾了关于SmB6 的一些重要实验结果，比如电输运测量，角分辨光电子能谱(ARPES), 表面形貌分析(STM) 等，并论述了如何通过这些关键的实验证据证实SmB6 的拓扑近藤绝缘物相。同时，我们也展示了SmB6 这一关联电子体系的其他奇异物性，包括中间价态在表面和体内的分离现象，以及量子振荡发现的体振荡信号等等。这些性质表明我们对SmB6 这一材料的理解仍然不充分，其中还有更为丰富的物理值得挖掘。

The exotic electronic properties of the topological Kondo insulator SmB6

The topological Kondo insulator (TKI) is an intrinsic electronic correlated topological system in which the bulk bandgap is originated from the Kondo correlation. Since the theoretical idea of TKI was proposed in 2010, SmB6 was predicted to be the first candidate topological Kondo insulator. In the last decade, SmB6 was investigated extensively by various experimental methods, and the accumulated evidence confirmed that SmB6 is a topological Kondo insulator. This review article presented some key experimental evidence, including electronic transportation measurements, ARPES study of low-energy band structure, and STM characterization of the surface. We also discussed how these experimental results establish the topological narrative of SmB6. Meanwhile, some extremely exotic properties like the 3D quantum oscillations and the bulk-surface valence seperation of SmB6 are exhibited. The related physical origin is still unknown and needs extra efforts to unveil the underlying physics.