Temperature effects on excited state of strong-coupling polaron in an asymmetric RbCl quantum dot

On the condition of strong electron-LO phonon coupling in an asymmetric RbCl quantum dot (QD), the first excited state energy (FESE), the excitation energy (EE), and the transition frequency (TF) between the first excited ground states (FEGS) of the polaron are calculated by using the linear combination operator and the unitary transformation methods. The variation of the FESE, the EE and the TF with the temperature, the transverse and longitudinal confinement strengths (TLCS) of the QD are studied in detail. We find that the FESE, the EE and the TF decreases (increases) with increasing temperature when the temperature is in lower (higher) temperature regime. They are increasing functions of the TLCS. We find three ways to tune the FESE, the EE and the TF via controlling the temperature and the TLCS.