Theory of electronic states and direct light absorption in the biconical (superellipsoidal) quantum dot

18th International Conference on Recent Progress in Many-Body Theories

Tshantshapanyan, A.A.^1 ; Dvoyan, K.G.^1 ; Vlahovic, B.^1

Department of Mathematics and Physics, North Carolina Central University, 1801 Fayetteville St., Durham

NC

27707, United States^1

关键词: Adiabatic approximations;    Center of gravity;    Effective potentials;    Electron energy spectrum;    Interband absorption;    Quadratic approximation;    Quantum transitions;    Theory of electronics;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/702/1/012011/pdf
DOI  :  10.1088/1742-6596/702/1/012011

来源: IOP

【 摘 要 】

The electronic states in the GaAs biconical (superellipsoidal) quantum dot (QD) in a strong and weak size quantization (SQ) regimes are theoretically investigated within the framework of the geometrical adiabatic approximation. An atypical linear term in the effective confining potential forms a family of non-equidistant sublevels in the electron energy spectrum, whereas the quadratic term leads to the appearance of the equidistant energy levels as a consequence of the symmetry of the QD. In the weak size quantization regime the motion of the exciton's center-of-gravity is quantized, which leads to the appearance of the additional Coulomb sub-levels in the energy spectrum of the QD. The direct interband absorption of light in the biconical QD is also considered in both strong and weak SQ regimes. The dependences of the absorption edge on QD geometrical parameters are revealed in the linear and quadratic approximations of the effective potential adiabatic terms. Corresponding selection rules for quantum transitions are obtained as well.