InAs/GaSb(001) valence-band offset: Independence of interface composition and strain

The InAs/GaSb(001) valence-band offset is calculated for the two inequivalent GaAs-like and InSb-like interfaces and found to coincide to within approximate to 30 meV. This result is rationalized and generalized to arbitrary composition profiles and induced strain by using a simple model, based on the linear response theory, which is validated by a number of accurate first-principles calculations for intermixed interfaces.