Impurity Effects in Two-Electron Coupled Quantum Dots: Entanglement   Modulation
  We present a detailed analysis of the electronic and optical properties of two-electron quantum dots with a two-dimensional Gaussian confinement potential. We study the effects of Coulomb impurities and the possibility of manipulate the entanglement of the electrons by controlling the confinement potential parameters. The degree of entanglement becomes highly modulated by both the location and charge screening of the impurity atom, resulting two regimes: one of low entanglement and other of high entanglement, with both of them mainly determined by the magnitude of the charge. It is shown that the magnitude of the oscillator strength of the system could provide an indication of the presence and characteristics of impurities that could largely influence the degree of entanglement of the system. 
Diego S. Acosta Coden, Rodolfo H. Romero, Alejandro Ferr\'on and   Sergio S. Gomez
cond-mat.mes-hall quant-ph