The effect of combination of magnetic field and low temperature on doped quantum wells

In this work, we study in the optical absorption of lightly doped and compensated GaAs–GaAlAs quantum wells in the presence of applied magnetic field at low temperatures. The maximum values of magnetic field and temperature are chosen to be View the MathML source and View the MathML source, respectively. The wave functions and energies of electrons bound to impurities are calculated variationally using hydrogen-like functions. The absorption coefficient is computed through the use of Fermi golden rule and the statistics of this system is made by a self-consistent calculation of the electrostatic potential generated by ionized impurities, while the convergence parameter is the electronic chemical potential. We focus our attention on 1s→2p± transitions. The results show that the range of frequency absorbed by the system stays unaltered in 1s→2p− transition and changes for the 1s→2p+ transition, presenting a shift to higher frequencies as the magnetic field increases. Another important result is the decrease of the absorption coefficient for the lowest part of the frequency range as the temperature decreases, turning the material almost transparent for those frequencies. This kind of information may be useful for further diagnosis of quantum well systems.