Many-body interaction in resonant tunneling of terahertz quantum cascade lasers

The time-dependent population inversion is simulated by the semiconductor Bloch equations with the many-body interaction in the resonant tunneling of the terahertz quantum cascade lasers (QCLs). When the many-body interaction is considered, the oscillation amplitude of the population inversion induced by the resonant tunneling is larger in the set up process, and the steady population inversion is little larger at the same dephasing time. The gain recovery process after the terahertz QCL being pumped by a nonchirped pi pulse is simulated. The gain recovery time is shorter with the many-body interaction being considered. These phenomena stem from the induced more intense resonant tunneling that caused by the renormalized energy detuning when the many-body interaction is considered. We show the importance of the many-body interaction in electron resonant tunneling between two neighbor periods of the terahertz QCL. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3498803]