Transverse laser dressing effects on the subband density of states in a 20-nm-wide GaAs/Al0.3Ga0.7As quantum well wire

The electronic subband structure of a relatively thick cylindrical quantum well wire irradiated by a non-resonant laser field is calculated within the one-band effective-mass approximation by using a finite element method. For the first time, the problem is solved for a large number of transverse electron modes in the wire. Exact laser-dressing effects on the lateral confinement potential are considered by using an analytical function. Important changes of the electron localization probability under intense laser field are described. The study reveals a competition between the quantum confinement and the laser field which breaks down the cylindrical symmetry of the wire and splits the degenerate electronic levels. A proper analysis of these results is accomplished by calculating the density of states function. Our central prediction is the non-uniform blueshift of the conduction subband structure which may be valuable for an active control of the optoelectronic properties related to intersubband and interband transitions in semiconductor quantum wires.

► The density of states in a quantum well wire under laser field is calculated.
► An analytical expression is proposed for the laser dressed confinement potential.
► The energies and wave functions are obtained by using a finite element method.
► The non-resonant laser field splits up the degenerate electronic levels.
► The transversal laser field non-uniformly blueshifts the subband levels.