Long-lived quantum coherence in a two-level semiconductor quantum dot

Abstract

In this paper, we present an analytical solution for the system of two-level semiconductor quantum dot. In addition, we discuss the rates of the photon radiative and phonon radiationless transitions from the excited state $$ (\alpha _{12}, \alpha _{21}),$$ the rate of processes of pure dephasing $$ (\gamma )$$ , the detuning parameter ( $$\Delta $$ ) and the Rabi frequency ( $$\Omega $$ ), on the atomic occupation probabilities ( $$\rho _{11}(t)$$ and $$\rho _{22}(t)),$$ the atomic population inversion ( $$\rho _{z}(t)),$$ the purity ( $$P_{A}(t)),$$ the von Neumann entropy (S(t)) and the information entropies ( $$H(\sigma _{x}),$$ $$H(\sigma _{y})$$ and $$H(\sigma _{z}))$$ . We clearly observe the emergence of long-lived quantum coherence phenomenon in all the curves for some special cases of $$\alpha _{12},$$ $$\alpha _{21}$$ , $$\gamma $$ , $$\Delta $$ and $$ \Omega .$$ Besides, the decay phenomenon is quite evident in the purity curves, which can be simply controlled by changing the values of $$\alpha _{12},$$ $$ \alpha _{21}$$ and $$\gamma .$$