Superlattice gain in positive differential conductivity region

David O. Winge, Martin Franckié, Andreas Wacker
2016 AIP Advances  
We analyze theoretically a superlattice structure proposed by A. Andronov et al. [JETP Lett 102, 207 (2015)] to give Terahertz gain for an operation point with positive differential conductivity. Here we confirm the existence of gain and show that an optimized structure displays gain above 20 cm$^{-1}$ at low temperatures, so that lasing may be observable. Comparing a variety of simulations, this gain is found to be strongly affected by elastic scattering. It is shown that the dephasing
more » ... e dephasing modifies the nature of the relevant states, so that the common analysis based on Wannier-Stark states is not reliable for a quantitative description of the gain in structures with extremely diagonal transitions.
doi:10.1063/1.4948538 fatcat:yhmfj7n2zvet5hx4ka375xbsvm