K-CENTER-DOT-P FINITE-DIFFERENCE METHOD - BAND STRUCTURES AND CYCLOTRON RESONANCES OF ALXGA1-XSB INAS QUANTUM-WELLS/

A simple theoretical six-band k.p finite difference method is develope d and applied to calculate the electronic band structures and electron ic Landau-level structures of the symmetric and asymmetric AlxGa1-xSb/ InAs quantum wells (QW's). The QW may exhibit a semiconductor-semimeta l transition by changing the Al composition in the AlxGa1-xSb layer. T he cyclotron-resonance splitting in the semiconducting structures is d ue to the large InAs conduction-band nonparabolicity and Zeeman effect . Broken-gap type-II semimetallic QW, in which the conduction-valence Landau-level mixing can yield a significant spin splitting for the InA s conduction-band Landau levels, produces a prominent electron double- line structure in the cyclotron-resonance spectra, whether the QW is s ymmetric or asymmetric. Strong oscillations in the electron cyclotron- resonance mass, amplitude, and linewidth are evident. The abnormal cyc lotron-resonance mass jumps, amplitude minima, and linewidth maxima oc curring near the even filling factors are due to the conduction-valenc e Landau-level mixing effect. These results are in good agreement with the experimental results.