论文标题
多播种系统中的常规和非常规异常速度
Conventional and unconventional anomalous velocities in multiband systems
论文作者
论文摘要
迄今为止，基于单波段近似，已经得出了异常的速度。在本文中，分解了多个能带的异常速度。结果表明，当考虑多个能带时，异常的速度实际上是从单带近似值下为零的速度项得出的。还表明，基于单波段近似的异常速度是从速度项中得出不当的，该速度项在考虑多个能带时变为零。此外，发现除了常规异常速度外，非常规类型的异常速度类型。这些非常规的异常速度垂直于电场，并且来自磁性brill rouin区域中磁性Bloch函数的奇异性。可以证实，常规和非常规的异常速度不仅可以从稳态扰动理论中得出，而且还可以源自时间依赖性的扰动理论，在这种扰动理论中，在这种理论中，产生均匀电场的时间依赖性向量被视为扰动。
The anomalous velocity has been derived so far based on the single-band approximation. In this paper, the anomalous velocity is derived accounting for multiple energy bands. It is shown that when multiple energy bands are considered, the anomalous velocity is actually derived from the velocity term which goes to zero under the single-band approximation. It is also shown that the anomalous velocity based on the single-band approximation is derived improperly from the velocity term which becomes zero in considering multiple energy bands. Furthermore, it is found that unconventional types of anomalous velocity may appear in addition to the conventional anomalous velocity. These unconventional anomalous velocities are perpendicular to the electric field and come from the singularity of the magnetic Bloch function in the magnetic Brillouin zone. It is confirmed that conventional and unconventional anomalous velocities can also be derived not only from the steady-state perturbation theory but also from the time-dependent perturbation theory in which a time-dependent vector potential yielding the uniform electric field is treated as a perturbation.
