Issue
EPL
Volume 82, Number 3, May 2008
Article Number 37004
Number of page(s) 4
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/82/37004
Published online 21 April 2008
EPL, 82 (2008) 37004
DOI: 10.1209/0295-5075/82/37004

Controllable electron g-factors in HgMnTe quantum spheres

Y.-H. Zhu and J.-B. Xia

National Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences P.O. Box 912, Beijing 100083, PRC

zhuyh@semi.ac.cn

received 30 November 2007; accepted in final form 18 March 2008; published May 2008
published online 21 April 2008

Abstract
The electronic structure and Landé electron g-factors of manganese-doped HgTe quantum spheres are investigated, in the framework of the eight-band effective-mass model and the mean-field approximation. It is found that the electronic structure evolves continuously from the zero-gap configuration to an open-gap configuration with decreasing radius. The size dependence of electron g-factors is calculated with different Mn-doped effective concentration, magnetic field, and temperature values, respectively. It is found that the variations of electron g-factors are quite different for small and large quantum spheres, due to the strong exchange-induced interaction and spin-orbit coupling in the narrow-gap DMS nanocrystals. The electron g-factors are zero at a critical point of spherical radius Rc; however, by modulating the nanocrystal size their absolute values can be turned to be even 400 times larger than those in undoped cases.

PACS
73.21.La - Quantum dots.
75.50.Tt - Fine-particle systems; nanocrystalline materials.
76.30.Fc - Iron group (3d) ions and impurities (Ti-Cu).

© EPLA 2008