Mechanism of terahertz lasing in SiGe/Si quantum wells

Intense terahertz (THz) stimulated emission from boron-doped SiGe/Si quantu m well structures with internal strain has been observed recently. We prese nt a theoretical calculation which shows the formation of resonant states, and explains the origin of the observed temperature dependence of the dc co nductivity under low bias voltage. Thus, the mechanism of THz lasing is pop ulation inversion of the resonant state with respect to the localized impur ity states. This is the same mechanism of lasing as in uniaxially stressed p-Ge THz lasers. (C) 2001 American Institute of Physics.