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Magneto-Optical Studies of Narrow Band-Gap Heterostructures with Type II Quantum Dots InSb in an InAs Matrix
Spin is the only electron internal degree of freedom, and utilizing it in the new generation of semiconductor devices is the main goal of semiconductor spintronics. Today spintronics focuses mainly on diluted magnetic semiconductors (DMS) where ferromagnetism and giant Zeeman splitting can be obtained due to exchange interaction between free carriers and Mn ions. Most of the work has been focused on II–VI DMS such as CdMnTe or ZnMnSe and some others. Enhanced magnetic properties of these materials exist only at cryogenic temperatures due to paramagnetic behavior of the magnetic ions. A lot of recent investigations have been focused on doping III–V semiconductors into a DMS state. Although III–V DMS demonstrate the higher Curie temperature, Mn is much less soluble here than in II–VI semiconductors [1]. Another issue is that in III–V compounds magnetic doping harmfully affects emission properties and, moreover, changes conductivity to p-type. We have proposed a new approach to the problem based on using narrow band--gap III–V compounds possessing the largest intrinsic electronic g-factor, which are InSb and InAs [2]. Large electron g-factor, small effective electron mass and strong spin–orbit interaction at these semiconductors provide pronounced spin-related phenomena in absence of magnetic doping.