Optical spectra and intensities of a magnetic quantum ring bound to an off-center neutral donorD0

Abstract

In this paper, we study the effect of the position of a positively charged impurity, or so-called donor, in a single-electron two-dimensional (2D) magnetic quantum ring, where the magnetic field is zero within the ring and constant elsewhere, on the low-lying spectra of such a neutral donor ${D}^{0}$ system (involving a positively charged impurity surrounded by a single electron) under perpendicular magnetic fields. The optical absorption spectra with their corresponding intensities between the ground state and the first excited state are calculated. The donor is located at a distance $d$ as measured vertically from the plane of the ring along the $z$ direction. The ground-state orbital angular momentum $(L)$ transitions induced by magnetic fields are overall presented in terms of a magnetic field versus donor position $(B\text{\ensuremath{-}}d)$ phase diagram. Dependences of the absorption spectra and their intensities on the layer thickness for the quasi-two-dimensional (q2D) magnetic quantum ring are also discussed.