The level-splitting effects of spin-orbit interaction on strong-coupling polaron in quantum dots with alkali halide

Abstract

Polaron properties in semiconductor quantum dots (QD) by the influence of Rashba spin-orbit (SO) interaction are studied. The relations of the ground state energy (GSE), the vibration frequency (VF), the confinement strength (CS), the interaction energy, and the effective mass (EM) of the polaron in the electron-phonon strong coupling region in a parabolic QD are derived by using linear combination operator (LCO) method and Lee-Low-Pines unitary transformation (LLPUT) methods. Numerical calculations for the RbCl and CsI crystal are performed, and the results show that the Rashba SO interaction makes the GSE and the EM of polaron split into two branches; the GSE and the EM will increase with the VF increasing. Whereas the interaction energy is sharply increased until the CS reaches a certain value, then it will sharply decrease. In alkali halides, the lower the outermost energy level is, the more stable the crystal material is, and the less it is affected by the Rashba effect. Moreover, in the Alkali halide, the lower the outermost energy level, the more stable the crystal material is, and the less affected by the Rashba effect.