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تسجيل مستخدم جديدNovel size effects on magneto-optics in the spherical quantum dots
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Manvir S. Kushwaha
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We embark on investigating the magneto-optical absorption in {em spherical} quantum dots {em completely} confined by a harmonic potential and exposed to an applied magnetic field in the symmetric gauge. This is done within the framework of Bohm-Pines RPA that enables us to derive and discuss the full Dyson equation that takes proper account of the Coulomb interactions. Intensifying the confinement or magnetic field and reducing the dot-size yields a blue-shift in the absorption peaks. However, the size effects are seen to be predominant in this role. The magnetic field tends to maximize the localization of the particle, but leaves the peak position of the radial distribution intact. The intra-Landau level transitions are forbidden.
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Here we embark on a thorough investigation of the magneto-optical absorption in semiconducting {em spherical} quantum dots characterized by a confining harmonic potential and an applied magnetic field in the symmetric gauge. This is done within the f
ramework of Bohm-Pines random-phase approximation that enables us to derive and discuss the full Dyson equation that takes proper account of the Coulomb interactions. As an application of our theoretical strategy, we compute various single-particle and many-particle phenomena such as the Fock-Darwin spectrum; Fermi energy; magneto-optical transitions; probability distribution; and the magneto-optical absorption in the quantum dots. It is observed that the role of an applied magnetic field on the absorption spectrum is comparable to that of a confining potential. Increasing (decreasing) the strength of the magnetic field or the confining potential is found to be analogous to shrinking (expanding) the size of the quantum dots: resulting into a blue (red) shift in the absorption spectrum. The Fermi energy diminishes with both increasing magnetic-field and dot-size; and exhibits saw-tooth-like oscillations at large values of field or dot-size. Unlike laterally confined quantum dots, both (upper and lower) magneto-optical transitions survive even in the extreme instances. However, the intra-Landau level transitions are seen to be forbidden. The spherical quantum dots have an edge over the strictly two-dimensional quantum dots in that the additional (magnetic) quantum number makes the physics richer (but complex). A deeper grasp of the Coulomb blockade, quantum coherence, and entanglement can lead to a better insight into promising applications involving lasers, detectors, storage devices, and quantum computing.
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