[8a-E218-1~11] 13.6 Nanostructures, quantum phenomena, and nano quantum devices

9:15 AM - 9:30 AM JST(12:15 AM - 12:30 AM UTC)

[8a-E218-2] Origin of free carrier for exciton response in a GaAs/AlAs multiple quantum well

〇Osamu Kojima¹, Kousuke Nakanishi¹, Xu Jiaming¹, Matthew Steer², Richard Hogg^2,3 (1.Chiba Inst. Tech, 2.Univ. of Glasgow, 3.Aston Univ.)

Keywords:

exciton,GaAs/AlAs multiple quantum well,nonlinear

We have investigated terahertz electromagnetic wave generation via difference-frequency mixing . Previously, we reported the possibility that free carriers, originating from the non-radiative relaxation of generated excitons, act as a factor disturbint the wave generation. In this study, to discuss the origin of these free carriers and their impact on the THz wave intensity, we measured the chopper-frequency dependence of photoreflectance spectra. As a result, we found the existence of carriers with a lifetime longer than the relaxation time of the excitons.