I am studying Transition Metal Dichalcogenides (TMDs) currently, and am having a hard with these two concepts.
I have read that the rashba effect only happens at interfaces. What about in a monolayer where inversion symmetry is broken (2H polymorph of a TMD)?
I understand that both are inversion breaking mechanisms - but rashba relates to structure inversion asymmetry, whereas Dresselhaus relates to bulk inversion asymmetry. I am not really sure what this means. Could someone explain this?
My understanding, and please correct me if I am wrong, is that at the monolayer limit (or odd number of layers), because of the out-of plane inversion asymmetry and in-plane mirror symmetry the crystal electric field, E, flows in-plane. The electrons also move in-plane with momentum K. Lorrentz transforming this, we see that the effective magnetic field is out of plane and the electrons spin will point out of plane (either up or down depending on k). This lifts the spin degeneracy. Is it right to say this is an effective Zeeman splitting with no external magnetic field?
I know rashba splitting lifts the degeneracy by shifting along the momentum axis, whereas this effective Zeeman splitting (is this dresselhaus?!?) would lift it along the energy axis.
I am pretty dang confused.
please help. thanks!