Femtosecond coherent spectroscopy of etched quantum wires

Electron Correlation Effects on the Femtosecond Dephasing Dynamics ofE22Excitons in (6,5) Carbon Nanotubes

“…This expression (eq 4) also reveals a possible explanation for the observed saturation behavior. Degenerate four-wave mixing results in reduced dimensional systems, 24,25 including an E 11 study, 8 have reported intensitydependent dephasing rates, as noted above.…”

Exciton dephasing in ZnSe quantum wires

“…[14][15][16][17][18] Until recently, the efforts to fabricate low-dimensional structures by lateral patterning have focused on III-V semiconductors, [19][20][21] for which degenerate FWM experiments are reported on reactive-ion etched structures. 22 Following the current search for blue-green laser structures based on ZnSe and Zn x Cd 1Ϫx Se quantum wells ͑QW's͒, high-quality II-VI structures are available for quantum wire and dot fabrication. 23,24 Since the wide-gap II-VI materials have in general a much larger exciton oscillator strength and thus a higher third-order nonlinearity than III-V materials, 25 they are better suited for the study of coherent transient phenomena in QWR's, which in general suffer by a small active volume.…”

“…͑1͒, we deduce a 1D scattering parameter of ␤ XX (1D) ϭ(1.4Ϯ0.4)ϫ10 Ϫ4 meV cm for the 23 nm QWR, which is close to the value of ␤ XX (1D) ϭ1.2ϫ10 Ϫ4 meV cm found in GaAs QWR's. 22 The extrapolated homogeneous linewidth ⌫ 0 is given by the remaining background scattering with free electrons, phonons, and photons ͑radiative damping͒. It shows a decrease with decreasing QWR size as already attributed to a reduced exciton-electron scattering due to localization and electron trapping.…”

Population dynamics and dephasing of excitons and electron-hole pairs in polytype wurtzite/zinc-blende InP nanowires

“…While this method has been widely applied to two-dimensional (2D) and bulk semiconductors, FWM experiments on epitaxially grown or etched quantum wires (QWRs) have proven to be challenging due to a reduced signal and strong Rayleigh scattering. Only a few groups reported on directional selective FWM in t-shaped GaAs QWRs 40 , in wet-chemical etched III-V [41][42][43] and II-VI QWRs [44][45][46] . The more advanced technique of heterodyne FWM (HFWM) 47 combines directionally selected FWM with a highly sensitive and selective heterodyne detection 48 providing sufficient suppression of the Rayleigh scattering background.…”