K⋅p Hamiltonian without spurious-state solutions

We developed a method to eliminate the spurious solutions of the k⋅p Hamiltonian by introducing an off-diagonal k² term. This results in a modification in the fourth-and higher-order terms in k of the band dispersion and does not affect the effective masses near the Γ point. We show that such a modification leads to a monotonic behavior of the conduction band as a function of k and thus eliminate the spurious solutions in the calculations of confined states for all popular III-V compounds.