Anomalous variations of optical properties in the vicinity of level anti-crossing in InAs/GaAs conical quantum dot nanowire

Abstract

The present study focuses on the investigation of the linear and nonlinear optical properties corresponding to electronic transitions in the vicinity of Level Anti-Crossing (LAC) points from a theoretical perspective. The system under consideration is an InAs conical quantum dot embedded in an infinite GaAs nanowire. The special configuration of the system leads to repeatedly LAC points in the energy spectrum of the system, three of which are considered here. The findings indicate a forward-backward shift in the energy location of the linear and non-linear Absorption Coefficient (AC) around the LAC. On the other hand, it is demonstrated that in this vicinity, AC for the transition to one of the crossing levels vanishes while that of the other maximizes. It is also found that, save for the lowest transition, the nonlinear component has essentially little share of the total AC, nearly for all incident photon energies, due to the limited and low values of the transition dipole moment.