Nonlinear absorption coefficient and optically detected electrophonon resonance in cylindrical GaAs/AlAs quantum wires with different confined phonon models

Effect of Electron-impurity Interaction on the Optical Absorption in A Quasi-one-dimensional Electron System

“…4 for the transition (0,1) → (0,2) (filled squares) and the transition (1,1) → (1,2) (filled circles). From the figure, one can see that FWHM decreases when the radius of the wire increases by the law FWHM = exp(−𝑎𝑅 2 − 𝑏𝑅 + 𝑐) for both cases of transition with different constants a, b and c. The decrease of FWHM with increasing the confinement size is in accordance with previous calculated results in low-dimensional systems using other theories [8][9][10][11][12][13]. The decrease of the FWHM of the resonance peaks when increasing wire radius can be explained follows.…”

“…One can see that as the wire radius increases, the resonant peaks shift to the smaller photon energy region (redshift). The redshift of the resonant peaks with increasing the confinement size of the systems has also been observed previously in some low-dimensional materials such as quantum well [10], semiconductor superlattices [11], and quantum wires [8,9]. Besides the position of the resonance peak, the full width at half maximum (FWHM) of the resonance peaks is also an important parameter when investigating the absorption spectrum.…”

“…In order to see clearly the characteristics of the absorption spectrum, we numerically evaluate the expression of absorption coefficient utilising specific parameters for the GaAs/AlAs quantum wire. The parameters used in the computation are taken from [8,9].…”

“…Therefore, we investigate the dependence of FWHM on the radius of wire. Using the profile method for determining FWHM [8][9][10][11], one obtain the FWHM of the absorption peaks at different values of the wire radius and show in Fig. 4 for the transition (0,1) → (0,2) (filled squares) and the transition (1,1) → (1,2) (filled circles).…”

Optical Absorption in Semiconductor Nanowire Mediated by Electron-Polar Optical Phonon and Spin-Orbit Interactions

“…The quantum theory of free carrier absorption (FCA) in bulk semiconductors for different scattering mechanisms is given in [2,3]. FCA has been studied theoretically in semiconductor quantum wells (QW) and quantum well wires(QWR) when the electrons are scattered by acoustic phonons [1,[4][5][6][7][8][9], optical phonons [6,[10][11][12][13][14], and by other lattice imperfections.…”