Stimulated emission due to the magnetoelectric photoeffect in narrow-gap semiconductors at the quantum limit

Quantum aspects of stimulated emission have been revealed in bulk narrow-gap semiconductors such as InSb and Hg1-xCdxTe with x=0.211, being excited at the quantum limit by the electric field Ey* induced by passing a current density J(//x) through the sample subjected to a transverse high magnetic field H(//z). The phenomenon has been demonstrated to be a useful tool for the spectroscopy of the band parameters, such as the energy gap epsilon g, the electron effective mass m1*, and the effective g-factor g1, being respectively determined as 0.18 eV m1*(0)=0.015m0 and g(0)=-47 for InSb at room temperature, in addition to such direct applications as a tunable infrared laser. The critical current density Jc for lasing has been observed to be 16-40 A cm2 for H=7 T in InSb at 80 K. The particularly low value of Jc can be explained from the extremely high value of the gain of the stimulated emission at the band edge at the quantum limit, which diverges to infinity in the high-field limit.