  Correlation effects on the electronic structure of half-metallic CrAs in
zinc-blende structure are studied for different substrate lattice constants.
Depending on the substrate the spectral weight of the non-quasiparticle states
might be tuned from a well developed value in the case of InAs substrate to an
almost negligible contribution for the GaAs one. A piezoelectric material that
would allow the change in the substrate lattice parameters opens the
possibility for practical investigations of the switchable (tunable)
non-quasiparticle states. Since the latter are important for the tunneling
magnetoresistance and related phenomena it creates new opportunities in
spintronics.
