Computational Nanoelectronics and Nanodevices Laboratory, National University of Singapore, Singapore.
Department of Physics, Harish-Chandra Research institute, Chhatnag Road, Jhusi, Allahabad, UP 211019, India.
Sci Rep. 2017 Mar 24;7:45016. doi: 10.1038/srep45016.
We study the quantum capacitance in a topological insulator thin film system magnetized in the in-plane direction in the presence of an out-of-plane magnetic field and hexagonal warping. To first order, the modification in quantum capacitance due to hexagonal warping compared to the clean case, where both the in-plane magnetization and hexagonal warping are absent, is always negative, and increases in magnitude monotonically with the energy difference from the charge neutrality point. In contrast, the change in the quantum capacitance due to in-plane magnetization oscillates with the energy in general, except when a certain relation between the inter-surface coupling, out of plane Zeeman energy splitting and magnetic field strength is satisfied. In this special case, the quantum capacitance remains unchanged by the in-plane magnetization for all energies.
我们研究了在面内方向磁化的拓扑绝缘体薄膜系统中的量子电容，同时存在面外磁场和六方扭曲。在一阶近似下，与不存在面内磁化和六方扭曲的清洁情况相比，由于六方扭曲引起的量子电容的修正总是负的，并且随着与电荷中性点的能量差单调增加。相比之下，由于面内磁化引起的量子电容的变化通常随能量而振荡，除非界面耦合、面外塞曼能分裂和磁场强度之间存在某种关系。在这种特殊情况下，面内磁化对所有能量的量子电容保持不变。
