Quenched dynamics of entangled states in correlated quantum dots

The time evolution of an initially prepared entangled state in the system of coupled quantum dots has been analyzed by means of two different theoretical approaches: equations of motion for all orders localized electron correlation functions, considering interference effects, and kinetic equations for the pseudoparticle occupation numbers with constraint on the possible physical states. Results obtained by means of different approaches were carefully analyzed and compared to each other. Revealing a direct link between concurrence (degree of entanglement) and quantum dots pair correlation functions allowed us to follow the changes of entanglement during the time evolution of the coupled quantum dots system. It was demonstrated that the degree of entanglement can be controllably tuned during the time evolution of quantum dots system.

Figure 1

Concurrence time evolution for different values of Coulomb interaction $U_1/\mathrm{\Gamma }=U_2/\mathrm{\Gamma }=U/\mathrm{\Gamma }$. ${\varepsilon }_1/\mathrm{\Gamma }={\varepsilon }_1/\mathrm{\Gamma }=7, T/\mathrm{\Gamma }=2$, and $\mathrm{\Gamma }=1$. Initial conditions are as follows: $N_S\left(0\right)=0.5, N_T\left(0\right)=0.5$.

Figure 2

Concurrence time evolution for different values of Coulomb interaction $U_1/\mathrm{\Gamma }=U_2/\mathrm{\Gamma }=U/\mathrm{\Gamma }$. ${\varepsilon }_1/\mathrm{\Gamma }={\varepsilon }_1/\mathrm{\Gamma }=7, T/\mathrm{\Gamma }=2$, and $\mathrm{\Gamma }=1$. Initial conditions are as follows: $N_S\left(0\right)=0.55, N_T\left(0\right)=0.45$.

Figure 3

Concurrence time evolution for different values of Coulomb interaction $U_1/\mathrm{\Gamma }=U_2/\mathrm{\Gamma }=U/\mathrm{\Gamma }$. ${\varepsilon }_1/\mathrm{\Gamma }={\varepsilon }_1/\mathrm{\Gamma }=7, T/\mathrm{\Gamma }=2$, and $\mathrm{\Gamma }=1$. Initial conditions are as follows: $N_S\left(0\right)=0.45, N_T\left(0\right)=0.55$.