Far-infrared optical spectrum of donor impurities in quantum dots in a magnetic field

摘要

We report calculations for far-infrared absorption in GaAs/Ga1-xAlxAs quantum dots doped with shallow-donor impurities in the presence of a magnetic field. The wave functions and the eigenvalues are obtained in the effective-mass approximation by using a variational approach in which the ground and excited magneto-impurity states are simultaneously obtained. The allowed intra-donor transitions have been investigated by using far-infrared radiation circularly polarized in the plane perpendicular to the magnetic field. We present results for the absorption coefficient as a function of the photon energy for several field strengths and arbitrary impurity positions. We have found that, as a consequence of the quantum dot confinement the infrared magneto-absorption strongly depends on the position of the impurity in the dot. [References: 17]