Donor-bound electrons in quantum rings under magnetic fields

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Amado, M.
Lima, R. P. A.
González-Santander de la Cruz, Clara
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American Physical Society
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We theoretically study donor-bound electron states in two-dimensional quantum rings of finite width. A strong magnetic field is applied perpendicular to the plane of the quantum ring. The resulting electronic states are obtained within the effective-mass approximation. For on-center donors, the radial Hamiltonian for the envelope function is exactly diagonalized, and the corresponding energy levels for different angular momenta are studied as a function of the applied magnetic field. Confinement properties change rapidly with the external magnetic field. An abrupt change of the localization properties appears at a critical magnetic field, since the electron is mainly localized around the impurity. This transition gives rise to well-defined anticrossing of levels as a function of the magnetic field. Intraband transitions are found to carry relevant information of these confining properties of the rings.
© 2007 The American Physical Society. The authors thank T. V. Bandos, D. Granados, and J. M. García for helpful discussions. This work was supported by MEC Project MOSAICO. R.P.A.L. acknowledges financial support from MEC through the Juan de la Cierva program.
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