Before revision: The Rashba effect has a similar energy band splitting due to spin-orbit interaction, but the asymmetry comes from the either from the bulk asymmetry of uniaxial crystals (e.g., of wurtzite typeE.
After revision: The Rashba effect has a similar energy band splitting due to spin-orbit interaction, but the asymmetry comes either from the bulk asymmetry of uniaxial crystals (e.g., of wurtzite typeE.