Dresselhaus effect in bulk wurtzite materials

Abstract

The spin-splitting energies of the conduction band for ideal wurtzite materials are calculated within the nearest-neighbor tight-binding method. It is found that ideal wurtzite bulk inversion asymmetry yields not only a spin-degenerate line ͑along the k z axis͒ but also a minimum-spin-splitting surface, which can be regarded as a spin-degenerate surface in the form of bk z 2 − k ʈ 2 =0 ͑b Ϸ 4͒ near the ⌫ point. This phenomenon is referred to as the Dresselhaus effect ͑defined as the cubic-ink term͒ in bulk wurtzite materials because it generates a term ␥ wz ͑bk z 2 − k ʈ 2 ͒͑ x k y − y k x ͒ in the two-band k • p Hamiltonian.

Spin dynamics in semiconductors

“…I Q can be written as I Q,s 1 ,s 2 = s 1 |e iQ·r |s 2 = δ σ 1 ,σ 2 F (m 1 , m 2 , q y , a y )F (n 1 , n 2 , q x , a x ), with F (m 1 , m 2 , q, a) being expressed as Eq. (248). For small spin polarization, the contribution from the Hartree-Fock term in the coherent term is negligible [41,42,44] and the spin precession is determined by the spin-orbit coupling,ρ h…”

“…10 In contrast to the zincblende semiconductors such as GaAs, the existence of hexagonal c-axis in wurtzite semiconductors leads to an intrinsic wurtzite structure inversion asymmetry in addition to the bulk inversion asymmetry [246,247]. Therefore, the electron spin splittings include both the Dresselhaus effect [245,248] (cubic in k) and Rashba effect (linear in k) [124,125,[249][250][251][252][253][254]. In a recent work by Fu and Wu [245], a Kane-type Hamiltonian was constructed and the spin-orbit coupling for electron and hole bands were investigated in the full Brillouin zone in bulk ZnO and GaN.…”

Theory of electron spin relaxation in ZnO

“…10,26,28 The parameter b is roughly equal to four for all wurtzite materials. 28 Note that there is no spin splitting along the hexagonal axis ͑z͒.…”

Influence of spin–orbit interactions on the polaron properties in wurtzite semiconductor quantum well

“…where m * is the electron effective mass in the absence of electronphonon and SO couplings, p x and p y are the electron momentum operators, V z c ( ) is a nanoscale confinement potential, which confines the electrons only along the z direction, R α is the Rashba [45] and D γ and b 4.28 = Dresselhaus SO coupling parameters [46], [48], x σ and y σ are Pauli spin matrices. The well-known solution of eigenvalue problem of Hamiltonian H el can be given as [38]:…”

“…Particularly, it is shown, that in bulk wurtzite structures, there are two wurtzite bulk inversion asymmetry effects; Dresselhaus effect which leads to a k 3 term and the wurtzite structure inversion asymmetry effect (which may be called as the Rashba effect) in bulk wurtzite which yields a linear-k term in the two-band kÁ p model [19,44]. The spin-splitting energies of the conduction band for ideal wurtzite materials are calculated [45] within the nearest-neighbor tight-binding method. It is found that ideal wurtzite bulk inversion asymmetry yields not only a spin-degenerate line but also a minimum-spin-splitting surface, which can be regarded as a spin-degenerate surface.…”