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

Abstract

Abstract We report calculations for far‐infrared absorption in GaAs/Ga 1– x Al x As 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.