Electronic band structure and Shubnikov de Haas effect in two dimensional semimetallic InAs/GaSb nanostructure superlattice
Abstract We have investigated the band structure E(d d1 d2) E(kz) and E(kp) respectively, as a function of the SL period, d, in the growth direction and in plan of InAs(d1 160 A)/GaSb(d2 105 A) type II superlattice, performed in the envelope function formalism with the valence band offset, L, of 510 meV at 4.2 K. For the ratio d1/d2 1.52, d and L dependence of the SL energy band gap show that the semiconductor to semimetal transition takes place at dc 173 A and Lc 463 meV. Therefore, this sample is semimetallic. The position of the Fermi level, EF 500.2 meV, indicates n type conductivity. The spectra of energy, E(kz, kp) show a negative band gap of 48.3 meV. The cutoff wavelength |lc| 25.7 um indicates that this sample can be used as a far infrared detector. Further, we have interpreted the minima of the magnetoresistance oscillations, Shubnikov de Haas effect, observed by D. M. Symons et al.