Wigner Function Formalism for Zero Magnetic Field Spin Dependent   Resonant Tunneling Structures
  We develop a Wigner function representation of the quantum transport theory of the conduction band electrons in Rashba effect resonant tunneling structures with a phonon bath. In narrow band gap heterostructures, spin splitting occurs mainly as a result of inversion asymmetry in the spatial dependence of the potential or as a result of external electric field. This "zero magnetic field spin splitting" is due to the Rashba term in the effective mass Hamiltonian. The quantum transport equations are derived using multi-band non-equilibrium Green's function formulation in generalized Kadanoff-Baym ansatz. 
Mehmet Burcin Unlu, Hong-Liang Cui