论文标题
了解半导体价质量
Understanding Semiconductor Valence Mass
论文作者
论文摘要
Bloch定理在数学上证明，在周期性的晶体中，电子可以获取负质量。目前的工作旨在为为什么这样做提供物理上的理解。我们依次分析了3倍轨道价状态耦合到（i）传导带中的非分级轨道水平，（ii）传导带中的3倍轨道水平，以及（iii）通过自旋轨道相互作用的旋转状态。我们表明，价电子对晶体轴的势头获得负质量并不是一件容易的事：不仅有必要与脱位轨道传导水平耦合，而且还必须通过旋转量轴诱导的3倍价sisspace的对称性破坏对称性subspace。由于这种相互作用的相对论起源，因此负价质量的存在构成了量子相对性的意外特征。
The Bloch theorem mathematically proves that in a periodic crystal, electrons can acquire a negative mass. The present work aims to provide a physical understanding for why this is so. We successively analyze the consequences of the 3-fold orbital valence state coupling to (i) a non-degenerate orbital level in the conduction band, (ii) a 3-fold orbital level in the conduction band, and (iii) spin states through spin-orbit interaction. We show that it is not at all trivial for valence electrons to acquire a negative mass for whatever their momentum with respect to the crystal axes: it is necessary to not only have a coupling to a degenerate orbital conduction level, but also a symmetry breaking of the 3-fold valence subspace by the spin quantization axis, as induced by spin-orbit interaction. Due to the relativistic origin of this interaction, the existence of negative valence masses thus constitutes an unexpected signature of quantum relativity.
