Detection of Rashba spin splitting in 2D organic-inorganic perovskite via precessional carrier spin relaxation

Ultrafast acoustic phonon scattering in CH3NH3PbI3 revealed by femtosecond four-wave mixing

“…The Rashba effect results from the breaking of inversion symmetry in conjunction with spin-orbit coupling 32,33 , which is large in the hybrid perovskites owing to the incorporation of heavy elements (Pb, I, Br). While inversion asymmetry is expected in 2D perovskites due to distortions of the lead-iodide octahedra induced by the competing effects of the small and long organic cations 42,43,57 , 3D perovskites such as CH 3 NH 3 PbI 3 are believed to possess inversion symmetry in the bulk of the crystal. Nevertheless, a strong surface Rashba effect is expected in the 3D case 50,[54][55][56] .…”