Seradjeh Babak, Wu Jiansheng, Phillips Philip
Department of Physics, University of Illinois, Urbana, Illinois 61801, USA.
Phys Rev Lett. 2009 Sep 25;103(13):136803. doi: 10.1103/PhysRevLett.103.136803.
Electrons in a metal subject to a magnetic field commonly exhibit oscillatory behavior as the field strength varies, with a period set by the area of quantized electronic orbits. Recent experiments on elemental bismuth have revealed oscillations for fields above 9 T that do not follow this simple dependence and have been interpreted as a signature of electron fractionalization in the bulk. We argue instead that a simple explanation in terms of the surface states of bismuth exists when additional features of the experiment are included. These surface electrons are known to have significant spin-orbit interaction. We show the observed oscillations are in quantitative agreement with the surface theory, which we propose to test by studying the effect of the Zeeman coupling in higher fields, dependence on the field orientation, and the thickness of the samples.
处于磁场中的金属中的电子，通常会随着场强变化呈现出振荡行为，其周期由量子化电子轨道的面积确定。最近对元素铋进行的实验表明，在高于9特斯拉的磁场中会出现振荡，这种振荡并不遵循这种简单的依赖关系，并且被解释为体相中电子分数化的一个特征。相反，我们认为，当纳入实验的其他特征时，铋的表面态存在一个简单的解释。已知这些表面电子具有显著的自旋轨道相互作用。我们表明，观察到的振荡与表面理论在定量上是一致的，我们建议通过研究更高磁场中塞曼耦合的效应、对场取向的依赖性以及样品的厚度来对该理论进行检验。
