束缚施主电子与Si29核超精细作用的各向异性

本文利用Si中浅能级施主的有效质量波函数,计算了束缚施主电子与Si²⁹核超精细作用的等效自旋哈密顿量。超精细作用中不同谷的Bloch函数之间,相干效应非常明显,超精细作用的各向异性主要是由谷间相干效应决定的。在强场近似下求出了Si²⁹核的核磁共振频率的表示式,定量地解释了Feher的实验结果,并且可以由实验定出谷间磁偶极相互作用矩阵元。从正交干面波的观点出发进行了计算,与实验结果比较定出了导带底布洛赫函数中2P心态波函数的组合系数的大小为0.20。指出了利用双共振方法及其压力效应有可能测定导带底的波矢及有效质量波函数的各向异性分布。

ANISOTROPIC HYPERFINE INTERACTION OF SHALLOW DONOR ELECTRON WITH Si29 NUCLEUS

The spin Hamiltonian of the hyperfine interaction between a shallow donor and the Si²⁹ nuclei has been derived on the basis of the effective mass wave function. The interference effect between the Bloch functions of different valleys is shown to be largely responsible for the anisotropy of the electron-nuclear hyperfine interaction. An expression for the resonance frequency was derived in the high field approximation. The theory is shown to account for the experimental observations of Feher on the anisotropic hyperfine interaction quantitatively. The coefficient of the 2p core function in the OPW conduction band edge Bloch functions has been determined by comparison with Feher's results to be 0.20 approximately. It is pointed out that on the basis of the theory given, the positions of the conduction band minima and the anisotropy of the donor effective mass wave function can be precisely determined by the method of ENDOR and its pressure effects.