Excitons in topological Kondo insulators: Theory of thermodynamic and transport anomalies in SmB6
Excitons in topological Kondo insulators: Theory of thermodynamic and transport anomalies in SmB6
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DOI：
10.1103/physrevlett.118.096604
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发表时间：
2017-03-03
影响因子：
8.6
通讯作者：
Cooper, Nigel R.
中科院分区：
文献类型：
--
作者：
Knolle, Johannes;Cooper, Nigel R.
近藤绝缘材料不属于弱绝缘体、相关带绝缘体和莫特绝缘体的常见二分法。它们在高温下是金属的，但在低温下类似于带状绝缘体，因为相互作用引起的带隙打开。第一个发现的近藤绝缘体 (KI) SmB6 预计会形成拓扑 KI (TKI)。然而，自从它被发现以来，人们观察到的热力学和输运异常现象无法用理论解释。在强磁场中的比热、热传输和量子振荡实验中可以看到电荷间隙内集体模式的神秘特征。在这里，我们证明 TKI 容易形成激子和磁激子。这些电荷中性的复合颗粒可以解释 SmB6 中长期存在的异常现象。
Kondo insulating materials lie outside the usual dichotomy of weakly versus correlated-band versus Mott-insulators. They are metallic at high temperatures but resemble band insulators at low temperatures because of the opening of an interaction-induced band gap. The first discovered Kondo insulator (KI) SmB6 has been predicted to form a topological KI (TKI). However, since its discovery thermodynamic and transport anomalies have been observed that have defied a theoretical explanation. Enigmatic signatures of collective modes inside the charge gap are seen in specific heat, thermal transport, and quantum oscillation experiments in strong magnetic fields. Here, we show that TKIs are susceptible to the formation of excitons and magnetoexcitons. These charge neutral composite particles can account for long-standing anomalies in SmB6.