Crystal-Field and Strain Effects on Minimum-Spin-Splitting Surfaces in Bulk Wurtzite Materials

Spin splitting in bulk wurtzite AlN under biaxial strain

“…Here, c wz ¼ c 0 þ c 0 and k wz ¼ k 0 þ k 0 . 10,11 The spin-splitting energy (dE) can be, therefore, described by 10,11 …”

“…The extension of the 2KP parameters as functions of external strains obtained from our previous research, which can be referred from Ref. 11. Figure 1 shows the spin splitting as a function of k == under various external strains (e xx ¼ À3.00%, 0%, and 3.00%) with k z ¼ 0 (p/c).…”

“…In bulk wurtzite semiconductors, there are also two types of wurtzite bulk inversion asymmetry (WBIA) effects. 5,[10][11][12][13] In the nearest-neighbor linear combination of atomic orbitals (LCAO) model, the ideal wurtzite structure yields only the type-II WBIA effect (called the Dresselhaus effect in Ref. 10), while deviations from the ideal structure caused by the crystal field or strain yield the type-I WBIA effect (called the Rashba effect in Ref.…”

“…10), while deviations from the ideal structure caused by the crystal field or strain yield the type-I WBIA effect (called the Rashba effect in Ref. 11). The type-II WBIA effect induces a cone-shaped minimum-spin-splitting (MSS) surface in the ideal wurtzite Brillouin zone.…”

“…Such a shape-controllable MSS surface also makes the wurtzite material a potential candidate for spintronic devices. 5,10,11 Based on the mechanics of spinorbit interaction, the interplay between Rashba and Dresselhaus effects will determine the shape of MSS surface of wurtzite aluminum nitride (AlN), which is crucial information in the band-engineering of AlN-based materials for spintronic application. Consequently, the role of biaxial strain and its influence on the MSS surface have to be solved when one wants to engineer the AlN-based materials for spintronic devices.…”