Theory of ESR Line Width in n-Type InSb

Anisotropic spin-dependent energy \(δ₀(E){σ·κ̂}({κ̂}~{O}(k³))\), σ : Pauli matrix), introduced by Rashba and Sheka in their study of the combined resonance in III-V compounds, provides a broadening of the Zeeman level. However, the level broadening is extremely narrowed by frequent scattering of the conduction electrons induced by ionized impurity centers. The present mechanism, together with the spin-flip processes related to the ionized impurity scattering and the LO-phonon exchange, gives a qualitative explanation for the observed ESR line width of the degenerate samples in n-InSb.