Band structure and intersubband absorption in modulation-doped V-groove quantum wires

A self-consistent nonparabolic calculation of the band structure and intersubband absorption in a V-groove-quantum-wire are presented and analyzed with respect to doping concentration, geometry, and temperature. A comparison with a parabolic flatband model shows that both the self-consistency and the nonparabolicity considerably affect subband edges and the intersubband absorption which are studied when both effects are taken into account. The absorption spectra exhibit a prominent peak in the terahertz region (wavelength range lambda(X)=55-95 mu m) for the polarization in the direction of the weak confinement (X), while for polarization in the direction of the strong confinement (Y), it shows two groups of peaks, one in a slightly lower wavelength range than for the X polarization, and the second for lambda(Y)=8-13 mu m. Technological parameters considered in our analysis can be used to tailor and adjust the absorption spectra for various applications in the terahertz spectral range. (c) 2007 American Institute of Physics.