Orbital magnetization of the electron gas on a two-dimensional kagomé lattice under a perpendicular magnetic field
Orbital magnetization of the electron gas on a two-dimensional kagomé lattice under a perpendicular magnetic field
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DOI：
10.1007/s11433-012-4872-9
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发表时间：
2012-08
期刊：
影响因子：
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通讯作者：
Zi-Gang Yuan;Zhigang Wang;Z. Fu;Shushen Li;Ping Zhang
中科院分区：
文献类型：
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作者：
Zi-Gang Yuan;Zhigang Wang;Z. Fu;Shushen Li;Ping Zhang
从理论上研究了垂直磁场作用下二维Kagomé晶格上电子气的轨道磁化。晶格几何与磁场的相互作用在磁布里渊区产生了非平凡空间的陈不变量，从而对磁化特性产生了深刻的影响。我们表明，在磁化的贝里相位项给出了顺磁性的贡献，而由磁布洛赫带的磁响应所带来的常规项产生抗磁性的贡献。结果，这两个分量的叠加在改变电子填充因子时引起磁化曲线中的精细振荡结构。这种振荡行为和Hofstadter能谱之间的关系，揭示了通过选择性地讨论的磁化强度和它的两个组件在相称的磁通关闭= 1/4，1/3，和1/6，分别。特别是，我们揭示了作为一个典型的例子的分形结构的磁振荡通过调谐公度通量aroundf= 1/4。还讨论了有限温度对磁化强度的影响。
The orbital magnetization of the electron gas on a two-dimensional kagomé lattice under a perpendicular magnetic field is theoretically investigated. The interplay between the lattice geometry and magnetic field induces nontrivialk-space Chern invariant in the magnetic Brillouin zone, which turns to result in profound effects on the magnetization properties. We show that the Berry-phase term in the magnetization gives a paramagnetic contribution, while the conventional term brought about by the magnetic response of the magnetic Bloch bands produces a diamagnetic contribution. As a result, the superposition of these two components gives rise to a delicate oscillatory structure in the magnetization curve when varying the electron filling factor. The relationship between this oscillatory behavior and the Hofstadter energy spectrum is revealed by selectively discussing the magnetization and its two components at the commensurate fluxes off= 1/4, 1/3, and 1/6, respectively. In particular, we reveal as a typical example the fractal structure in the magnetic oscillations by tuning the commensurate flux aroundf= 1/4. The finite-temperature effect on the magnetization is also discussed.