Hot electron Landau level lifetime in GaAs/GaAlAs heterostructures

Saturation spectroscopy of carriers in semiconductor multiple-quantum-well structures

“…(5) T, at peak absorption is then fitted to the measured spectrum with an appropriate value of T. In the above analysis, we have ignored multiple internal reflection due to the very slight difference of index of refraction of well material and barrier material. The value of o is determined empirically for each of the samples from low laser intensity transmission curves by taking a in each layer to be Nu, where N is the total electron/hole density per layer.…”

Electronically tunable laser with automatic alignment along the Bragg angle in an acoustooptic deflector

“…With these analyses, a lifetime (the only adjustable parameter to he determined from a fit of absorption intensity versus laser intensity to the measurements) of -7 = 1.2 F 0.8 ns is inferred. Based on the analyses for sample 2 and 3, there is no indication, within the uncertainty of the experimental data, of any carrier density dependence of 7 as reported in the bulk [2] and in single heterostructures [4] in which LLS are not coupied to any confinement subband. .…”

“…In principle, by measuring the intensity dependence of the resonance absorption the relaxation rate (and thus the lifetime) ofcarriers in the excited states can be extracted. Far-inkared (FIR) magnetoimpurity absorption saturation in bulk GaAs [l] and absorption saturation of Landau levels (LL) in both bulk GaAs [2,3] and GaAs/AlGaAs single heterostructures [4,5] have been reported with relatively low-intensity excitation ( 6 1 W cm-'). Recently, optical saturation of intersubband absorption in GaAs/AlGaAs quantum wells was achieved with much stronger excitation (-1 MW cm-z) at 10-12 pm [SI.…”

Exchange interaction effects in inter-Landau level Auger scattering in a two-dimensional electron gas

“…In the past years a considerable amount of work has been done on the determination of the electron lifetime in the excited Landau levels (LL) in a two-dimensional electron gas (2DEG) [1][2][3][4][5]. It was found that electron-electron (ee) scattering is the dominant relaxation mechanism, when the emission of LO phonons is suppressed off the magnetophonon resonance conditions [6,7].…”