Nontrivial topological valence bands of common diamond and zinc-blende semiconductors

Negative thermal expansion of diamond and zinc-blende semiconductors.

Experimentally it is well known that diamond and zinc-blend semiconductors show an "unusual" (i.e. , negative) thermal expansion at about 100 K. We performed density-functional-theory calculations of thermodynamic potentials (i.e. , total energies and entropies) for perfect crystals, to study the temperature dependence of the lattice parameter. The origin of the negative expansion eff'ect is tr...

Comment on electro-optic effect and valence-band mixing in zinc-blende semiconductors

Importance of second-order piezoelectric effects in zinc-blende semiconductors.

We show that the piezoelectric effect that describes the emergence of an electric field in response to a crystal deformation in III-V semiconductors such as GaAs and InAs has strong contributions from second-order effects that have been neglected so far. We calculate the second-order piezoelectric tensors using density-functional theory and obtain the piezoelectric field for [111]-oriented In(x...

Multilayers of Zinc-Blende Half-Metals with Semiconductors

We report on first-principles calculations of multilayers of zinc-blende half-metallic ferromagnets CrAs and CrSb with III-V and II-VI semiconductors, in the [001] orientation. We examine the ideal and tetragonalised structures, as well as the case of an intermixed interface. We find that, as a rule, half-metallicity can be conserved throughout the heterostructures, provided that the character ...

Zener model description of ferromagnetism in zinc-blende magnetic semiconductors

Ferromagnetism in manganese compound semiconductors not only opens prospects for tailoring magnetic and spin-related phenomena in semiconductors with a precision specific to III-V compounds but also addresses a question about the origin of the magnetic interactions that lead to a Curie temperature (T(C)) as high as 110 K for a manganese concentration of just 5%. Zener's model of ferromagnetism,...