Theory of the g-Factor in Graphite Intercalation Compounds

Abstract

Based on Blinowski-Rigaux’s band model, an expression for the g-shift (Δg) in stage-4 donor graphite intercalation compound has been derived by using the Dresselhaus-Dresselhaus spin-orbit Hamiltonian. If the bands are labeled as B⁻, A⁻, B⁺ and A⁺ in order of energy E_s, g-shifts for A^±- and B^±-states are of opposite sign to each other, and in most cases |Δg(A⁻)|>|Δg(B⁻)|>|Δg(B⁺)|>|Δg(A⁺)|. Since the higher the energy E_s the less the state density, the total g-shift Δg=Σ_sΣ_EsΔg(E_s)δ(E_s−E_F)⁄Σ_sΣ_Esδ(E_s−E_F) is very small in agreement with the observations: If the Fermi level crosses the four bands Δg becomes essentially zero, while the crossing with the three bands A⁻, B⁺ and A⁺ makes Δg finite but still small in the magnitude. Each Δg(E_s) is very sensitive to the potential difference between the bounding and interior layers.