Spin-Orbit-Coupling, Electric-Field and Free-Carrier-Screening Effects on Valence Band Structure of Strained Coupled Quantum Wells
Languages of publication
We have calculated the structure of the valence bands and its dependence on the electric field and the density of free carriers in a lattice mismatched single and double quantum well. Our calculation is based on simultaneous solving of the effective mass equation for the envelope functions and Poisson's equation. The 6×6 Luttinger-Kohn Hamiltonian is diagonalized into two 3×3 blocks by a unitary transformation. We have shown how including the coupling between spin-orbit split-off band and light- and heavy-hole bands influences the shape of the valence bands. Further it has been found that at high densities of the free carriers and at non-zero electric field, the free-carrier screening affects the valence band structure and wave functions. This effect is considerably pronounced in double quantum well because of large spreading of the quantum states. The studying of the above effects is useful for band-structure engineering.
Publication order reference