Valence-band effective-potential evolution for coupled holes

TL;DR

This paper investigates how the effective potential profiles in layered heterostructures of III-V semiconductors evolve with increasing band mixing of light and heavy holes, revealing limitations of standard models and proposing a more adaptable approach.

Contribution

It introduces a root-locus-like method to analyze the evolution of effective potentials in multiband systems with varying valence-band mixing, highlighting the need for mutable band offset profiles for light holes.

Findings

Standard fixed-height potential models are reliable for heavy holes.

Light holes require a mutable band offset profile as in-plane kinetic energy varies.

Effective potential profiles significantly change with valence-band mixing.

Abstract

We present the metamorphosis in the effective-potential profile of layered heterostructures, for several III-V semiconductor binary compounds, when the band mixing of light and heavy holes increases. A root-locus-like procedure, is directly applied to an eigenvalue quadratic problem obtained from a multichannel system of coupled modes, in the context of multiband effective mass approximation. By letting grow valence-band mixing, it is shown the standard fixed-height rectangular potential-energy for the scatterer distribution, to be a reliable test-run input for heavy holes. On the contrary, this scheme is no longer valid for light holes and a mutable effective \emph{band offset} profile has to be considered instead, whenever the in-plane kinetic energy changes.