Ga1- xInxAsySb1- y/GaSb spherical quantum dot in a magnetic field

Abstract

Quaternary semiconductor alloys type-I are appropriated materials for heterostructure devices because they provide a natural form to tune the magnitude of the band gap so that it can operate in the mid-infrared (mid-IR) wavelength range. However electron spin degree of freedom and the electron spin splitting g-factor provide a new pathway to the development of a practical quantum communication systems, because the effective g-factor for electrons in III-V semiconductors vary as a function of the chemical concentration. We investigated theoretically electron g-factor in bulk Ga(1-x)In(x)As(y)Sb(1-y) matched to GaSb and the Zeeman effect as well as the Landau levels in GaSb/Ga(1-x)In(x)As(y)Sb(1-y)/GaSb spherical quantum dot heterostructure under the framework of Kane eight-band effective-mass model, in which the mixing of the states in the lower conduction band and the highest valence bands is taken into account. Our calculations show that bulk electron g-factor values are in the range between the electron g-factor measured in bulk GaSb when x -- 0 (g =-9.25) and that measured in InAs when x --1 (g =-18.08), but there is a notable minimum in the g-factor value (g -- -23.14) at x -- 0 . 67. In GaSb/Ga(1-x)In(x)As(y)Sb(1-y)/GaSb spherical quantum dot our calculations show that the electron g-factor decreases as the radius increases reaching the value for the quaternary in bulk for a given In concentration, x, and increases when the radius decreases, approaching to the value in the barrier material, when R -- 0. Also for higher values of concentration of In, the g-factor as a function of R moves to the g-factor bulk limit