自旋轨道耦合作用的等效磁场

AN EFFECTIVE MAGNETIC FIELD OF SPIN-ORBIT COUPLING

自旋与电荷一样,是电子的固有属性,电子的周期性轨道运动产生的磁场与电子的自旋磁矩相互作用,这种磁相互作用就是自旋轨道相互作用。在原子物理学中,这种自旋轨道作用会影响原子光谱的精细结构,然而教材中缺少自旋轨道耦合作用在二维半导体材料中的微观描述。本文将引入Rashba和Dresselhaus自旋轨道耦合作用的哈密顿量,研究单电子在无外场下二维平面内运动,讨论一种或者两种自旋轨道耦合的哈密顿量表示。通过自旋与等效磁场耦合的塞曼能量表示,本文计算了本征态下不同自旋轨道耦合作用下的等效磁场,从而有助于探索二维半导体材料中不同自旋轨道耦合作用下的物理特性。

Spin,like charge,is an internal property of electrons.The magnetic field generated by the periodic orbital motion of electrons interacts with their spin magnetic moment,which is known as spin orbit interaction.In Atomic Physics,it is pointed out that this spin orbit interaction can affect the fine structure of atomic spectra,but the textbook lacks a microscopic description of spin orbit coupling in two-dimensional semiconductor materials.In this paper,we will introduce the Rashba and Dresselhaus spin-orbit coupling Hamiltonian to study the motion of a single electron in a two-dimensional plane in the absence of an external field,and discuss the Hamiltonian representation of one or two types of spin orbit coupling.By using the Zeeman energy representation of spin and equivalent magnetic field coupling,we calculate the effective magnetic field in the eigenstates.It is meaningful to study the novel physics induced by different spin-orbit interactions in two-dimensional semiconductors.