Mapping out the emergence of topological features in the highly alloyed topological Kondo insulators Sm1−xMxB6(M=Eu,Ce)
Mapping out the emergence of topological features in the highly alloyed topological Kondo insulators Sm1−xMxB6(M=Eu,Ce)
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DOI：
10.1103/physrevb.104.115118
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发表时间：
2021-08
影响因子：
3.7
通讯作者：
Yishuai Xu;Erica Kotta;M. Song;B. Kang;J. W. Lee;B. Cho;Shouzheng Liu;T. Yilmaz;E. Vescovo-E.
中科院分区：
文献类型：
--
作者：
Yishuai Xu;Erica Kotta;M. Song;B. Kang;J. W. Lee;B. Cho;Shouzheng Liu;T. Yilmaz;E. Vescovo-E.
SmB 6是一种强关联材料，被认为是拓扑绝缘体和近藤绝缘体。最近的研究发现，拓扑表面状态和低温绝缘特性对磁性和非磁性杂质具有深刻的鲁棒性。本文利用角分辨光电子能谱（angleresolvedphotoemission spectroscopy，AES）研究了Sm$_{1-x}$M$_x$B$_6$（M=Eu，Ce）中拓扑电子结构随磁性掺杂和温度的变化。拓扑相干现象观察到前所未有的~ 30%Eu和50%Ce浓度，分别代表极端标称空穴和电子掺杂。理论分析表明，最近重新指定的拓扑反转带对称性提供了一个自然的路线来调和拓扑表面状态出现的持久性，即使绝缘间隙通过退相干丢失。
SmB6 is a strongly correlated material that has been attributed as a topological insulator and a Kondo insulator. Recent studies have found the topological surface states and low temperature insulating character to be profoundly robust against magnetic and non-magnetic impurities. Here, we use angle resolved photoemission spectroscopy to chart the evolution of topologically-linked electronic structure features versus magnetic doping and temperature in Sm$_{1-x}$M$_x$B$_6$ (M=Eu, Ce). Topological coherence phenomena are observed out to unprecedented ~30% Eu and 50% Ce concentrations that represent extreme nominal hole and electron doping, respectively. Theoretical analysis reveals that a recent re-designation of the topologically inverted band symmetries provides a natural route to reconciling the persistence of topological surface state emergence even as the insulating gap is lost through decoherence.