Electronic and optical responses of laser dressed triple concentric quantum rings in electric field

Abstract

ABSTRACT In this paper, we theoretically studied a 3D structure of GaAs/Al0.3Ga0.7As triple concentric quantum rings submitted to the combined action of a non-resonant intense laser and a static electric field. The 3D model was built using the cross-sectional profile of the structure that corresponds to a realistic experimental case of triple rings with different heights and widths. The electric field and the laser field have opposite influence on the energy levels, decreasing or increasing all studied levels, respectively. Linear or quadratic Stark effect can be seen in specific ranges of electric field values, depending on the anisotropy induced by the intense laser field, for given fields orientations. The observed anti-crossings are explained by wave-functions delocalisation from one ring to another or by symmetry exchange between the wave-functions of the inner ring. For the most deformed potential created by perpendicular orientation of electric field and intense laser polarisation, very large absorption peaks, blue-shifts, red-shifts or an oscillatory behaviour in peaks energy and amplitude are obtained in a controllable way by proper manipulation of the fields. This can be helpful for the tunability and optical features improvement of THz detectors or solar cells.