Dynamical equilibrium between magnetic ions and photocarriers in low Mn-doped single quantum dots
Résumé
For low Mn-doped Cd(Mn)Te/ZnTe single quantum dots, we report a nonlinear behavior of exciton energy as a function of magnetic field, which differs from the usual giant Zeeman effect. This effect is modeled by a positive feedback loop in the heating process of Mn spins by carriers photocreated in the vicinity of the dot. It results in a highly nonlinear and magnetic field dependent Mn spin heating process. This effect prevails when dealing with magnetic dot deposited on a thin two-dimensional layer and containing about 1% Mn. This shows that controlling the coupling between the magnetic dot and its local environment is a corner stone to achieve nanoscale spin manipulation.