Sublattice Reversal in AlAs/Ge/AlAs Heterostructures Grown on (113)A GaAs Substrate

摘要

We have demonstrated sublattice reversal (SR) in GaAs/Ge/GaAs heterostructures on high-index (113)B GaAs substrates grown by molecular beam epitaxy (MBE). SR can be used as an alternative and more versatile method to reverse the sign of x (second-order nonlinear susceptibility), which is essential in a novel terahertz (THz) device proposed by our group. THz signal results from difference-frequency generation using two-color lasers around 920 nm in this device. From the viewpoint of practical device applications, AlAs/Ge/AlAs heterostructures with a higher barrier layer are required to avoid the absorption of lasers. Noted that in our previous research, SR was not achieved in GaAs/Ge/GaAs heterostructures grown on the (113)A GaAs substrate.