Effect of electric field on the spectrum and the persistent current of a quantum ring with two electrons (II)---additional effect of a charged impurity
Wu Hong(吴洪)†
Department of Physics, School of Sciences, Jimei University, Xiamen 361021, China
Abstract This paper studies the effect of a~charged~impurity together with or without an external homogeneous~electric field~on a~quantum~ring threaded by a magnetic field $B$ and containing two electrons. The potential caused by the impurity has been plotted which is helpful to the understanding of the electronic structures inside the ring. The deep valley appearing in the potential curve is the source of localization, which affects seriously the Aharonov--Bohm oscillation (ABO) of the energy and persistent current. It also causes the fluctuation of the total orbital angular momentum $L$ of the pair of electrons. It is found that the appearance of the impurity reduces the domain of the fractional ABO. During the increase of $B$, the domain of the integral ABO may appear earlier when $B$ is even quite small. The transition from the localized states to extended states has also been studied. Furthermore, it has deduced a set of related formulae for a transformation, by which an impurity with a charge $e_p$ placed at an arbitrary point Rp is equivalent to an impurity with a revised charge $\tilde {e}_p$ placed at the $X$-axis with a revised radial distance $\tilde {R}_p$. This transformation facilitates the calculation and make the analysis of the physical result clearer.
Received: 08 October 2007
Revised: 03 January 2008
Accepted manuscript online:
(Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems)
Fund: Project supported by the Natural
Science Foundation of Fujian Province of China (Grant No T0650010).
Cite this article:
Wu Hong(吴洪) Effect of electric field on the spectrum and the persistent current of a quantum ring with two electrons (II)---additional effect of a charged impurity 2008 Chin. Phys. B 17 3026
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.
