In the envelope function treatment of quantum wells and superlattices, an effective mass Hamiltonian including corrections to the quadratic dispersion relation is commonly employed to describe non-parabolicity and other complications of the band structure. A careful definition of the boundary conditions used to connect the envelope functions at the interfaces is required to consistently take such higher order effects into account to a given order of approximation. It is possible to develop a single band scheme to describe the light-hole non-parabolicity implicitly accounting for the coupling to other bands. With respect to the conduction electron case, the coupling between the split-off and light-hole bands brings about qualitative changes in the boundary conditions. Model calculations show how the non-parabolicity affects the energy levels not only through the modified (i.e. non-quadratic) dispersion relation, but also through the consistently modified boundary conditions. The present simple theory compares favorably with experimental data and more refined theoretical treatments.

LIGHT-HOLE NONPARABOLICITY IN THE SINGLE BAND APPROXIMATION

LA ROCCA, Giuseppe Carlo;
1991

Abstract

In the envelope function treatment of quantum wells and superlattices, an effective mass Hamiltonian including corrections to the quadratic dispersion relation is commonly employed to describe non-parabolicity and other complications of the band structure. A careful definition of the boundary conditions used to connect the envelope functions at the interfaces is required to consistently take such higher order effects into account to a given order of approximation. It is possible to develop a single band scheme to describe the light-hole non-parabolicity implicitly accounting for the coupling to other bands. With respect to the conduction electron case, the coupling between the split-off and light-hole bands brings about qualitative changes in the boundary conditions. Model calculations show how the non-parabolicity affects the energy levels not only through the modified (i.e. non-quadratic) dispersion relation, but also through the consistently modified boundary conditions. The present simple theory compares favorably with experimental data and more refined theoretical treatments.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11384/7655
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