Quantum Amplifier with Spin-Polarized Electrons Injection
A promising idea to use the transport of spin-polarized conduction electrons in a magnetic hetero-structure in order to invert population of the charge-carrier spin level in one of its layers, aiming at creation of an active environment for the electromagnetic radiation amplification, has been realized in a number of FMС/SC structures in which FMС is a ferromagnetic conductor and SC is a semiconductor. The n-InSb single crystals, featured by a high mobility of charge carriers, narrow ESR line, and anomalously high absolute value of the negative g-factor (g = −52), were used as SC. The following materials were used as FMC playing a role of spin polarizer: (i) ferromagnetic semiconductors EuO0.98Gd0.02O and HgCr2Se4, (ii) Geisler alloys Co2MnSn, Ni2MnSn and Co2MnSb. We have demonstrated that the spin-polarized electrons injection into the n-InSb semiconductor from the above-mentioned ferromagnetic materials results in a generation of the laser-type electromagnetic radiation.
N.A. Viglin et al., "Quantum Amplifier with Spin-Polarized Electrons Injection", Solid State Phenomena, Vols. 168-169, pp. 43-46, 2011